How Many Indians?



     The Indians have shrunk back before our advance only after fierce and dogged resistance.  They were never numerous in the land, but exactly what their numbers were when the whites first appeared is impossible to tell.  Probably an estimate of half a million for those within the limits of the present United States is not far wrong; but in any such calculation there is of necessity a large element of mere rough guess-work.  Formerly writers greatly over-estimated their original numbers, counting them by millions.  Now it is fashionable to go to the other extreme, and even to maintain that they have not decreased at all.  The last is a theory that can only be upheld on the supposition that the whole does not consist of the sum of the parts; for whereas we can check off on our fingers the tribes that have slightly increased, we can enumerate scores that have died out almost before our eyes.  Speaking broadly, they have mixed but little with the English (as distinguished from the French and Spanish) invaders.  They are driven back, or die out, or retire to their own reservations; but they are not often assimilated.  Still, on every frontier, there is always a certain amount of assimilation going on, much more than is commonly admitted; and whenever a French or Spanish community has been absorbed by the energetic Americans, a certain amount of Indian blood has been absorbed also.

     --- Theodore Roosevelt (1858-1919), 26th President of the United States, The Winning of the West, 1889.

     In the year 1492, the West-Indies were discovered, in the following year they were inhabited by the Spaniards; a great company of the Spaniards going about 49 years agoe.  The first place they came to, was Hispaniola, being a most fertile Island, and for the bignesse of it very famous, it being no less than six hundred miles in compass.  Round about it lie an innumerable company of Islands, so throng'd with Inhabitants, that there is not to be found a greater multitude of people in any part of the world.  The Continent is distant from this about Two hundred miles, stretaching it self out in length upon the sea side for above Ten thousand miles in length.  This is already found out, and more is daily discovered.  These Countreys are inhabited by such a number of people, as if God had assembled and called together to this place, the greatest part of Mankinde.  ...  To these quiet Lambs [of Hispaniola], endued with such blessed qualities [previously described], came the Spaniards like most cruel Tygres, Wolves, and Lions, enrag'd with a sharp and tedious hunger; for these forty years past, minding nothing else but the slaughter of these unfortunate wretches, whom with divers kinds of torments neither seen nor heard of before, they so cruelly and inhumanely butchered, that of three millions of people which Hispaniola it self did contain, there are left remaining alive scarce three hundred persons. ... Now to come to the Continent, we are confident, and dare affirm upon our own knowledge, that there were ten Kingdomes of as large an extent as the Kingdome of Spain, joyning to it both Arragon, and Portugal, containing above a thousand miles every one of them in compass, which the unhumane and abominable villanies of the Spaniards have made a wilderness of, being now as it were stript of all their people, and made bare of all their inhabitants, though it were a place formerly possessed by vast and infinite numbers of men;  And we dare confidently aver, that for those Forty years, wherein the Spaniards exercised their abominable cruelties, and detestable tyrannies in those parts, that there have innocently perish'd above Twelve millions of souls, women and children being numbered in this sad and fatall list; moreover I do verily believe that I should speak within compass, should I say that above Fifty millions were consumed in this Massacre. ... For the Spaniards so contemned them (I now speak what I have seen without the least untruth) that they used them not like beasts, for that would have been tolerable, but looked upon them as if they had been but the dung and filth of the earth ... "

     --- Bartolomé de Las Casas, Tears of the Indians, translation by J. Phillips, 1656, of Brevísima Relación de la Destrucción de las Indias, 1552. 

     In his American Indian Holocaust and Survival:  A Population History Since 1492 (1987), Russell Thornton makes a comparison which for many is the benchmark genocide of the 20th century, or even in all recorded history:  "For [the American Indians] the arrival of the Europeans marked the beginning of a long holocaust, although it came not in ovens, as it did for the Jews.  The fires that consumed North American Indians were the fevers brought on by newly encountered diseased, the flashes of settlers' and soldiers' guns, the ravages of 'firewater', the flames of villages and fields burned by the scorched earth policy of vengeful Euro-Americans.  The effects of this holocaust of North American Indians, like that of the Hews, was millions of deaths.  In fact, the holocaust of the North American tribes was, in a way, even more destructive than that of the Jews, since many American Indian peoples became extinct."  This comparison, vivid as it is, suffers from the fact that Thornton is apparently considering "the Jews" as a homogeneous unit, while he's separating the American Indians into tribes.  One could no doubt subdivide the Jewish victims of the Nazi-led holocaust in such a way that some of the subgroups were rendered extinct.

     Demography is not an exact science in the way physics and chemistry are.  This is not a reference to use of probability and statistics, but rather to the unavailability or unreliability of sources.  Demography is an historical and not an experimental science.  The closest demography comes to being even an observational science is the use by demographers of census data.  The accuracy of censuses has improved in many times and places in comparatively recent times, but in the period before the Europeans came in large numbers to the Western Hemisphere, and for some time afterward, they were non-existent, or sketchy, especially so far as numbers of Indians were concerned.  In spite of all this, relatively simple mathematical models have often been used to estimate the sizes of populations of Indians during these earlier periods.

     An important factor in estimating American Indian population sizes is the occurrence of epidemic diseases before and after the Europeans came beginning in the 17th century.  In the collection Disease and Demography in the Americas (1992), edited by John W. Verano and Douglas H. Ubelaker, the latter editor has an article called "North American Indian Population Size: Changing Perspectives"  He discusses the importance of studying population sizes in the New World, and then says: Unfortunately, demographic data on American Indian population size from pre-European times to the present are incomplete and subject to interpretation.  There is no perfect approach to estimating population size:  all available data bases are flawed to some extent and require assumptions and interpretations to generate estimates. ... Archeological approaches look at site surface areas, house and mound frequency, quantity of refuse, settlement patterns, and poorly defined concepts such as ecological resource potential.  Population estimates generated from such sources must guess how long houses were occupied, how many persons lived in a house, just how many oysters make a meal or to what extent populations exploited their environment. ... Ethnohistorical approaches largely rely upon estimates made by early Europeans in contact with American Indian populations.  Even if such data were accurate, they may underestimate the pre-European population size since some major epidemics may have preceded actual European contact or at least contact by the particular European making the estimate."

     According to Ubelaker:  "Given the inadequacy and variable quality of census data during the period of initial historical contact, it is not surprising that scholars have turned to a variety of methods of estimating population size.  Some have relied on estimates of death rates utilizing early historical sources or epidemiological analogy, for example, assuming a particular disease impact and working back from a fixed historic estimate."  This adds the formidable uncertainties inherent in epidemiology to the uncertainties inherent in demography.  Ubelaker says:  "Contributions from physical anthropology involve demographic reconstruction from skeletal samples and delineation of disease profiles that augment ethnohistorical and archeological evidence. ... Such studies are limited primarily by sampling problems and the frustrations of obtaining accurate estimate of age at death and differential diagnosis of disease."

     Estimates of American Indian populations have varied widely.  In 1541, Bartolomé de las Casas, author of a primary source on early treatment of Indians by the Spanish, argues that 15 million Indians died in the West Indies alone between 1500 and 1540.  In contrast, A. L. Kroeber estimated that just over 8 million Indians occupied the entire Western hemisphere in 1492.  (Cited by Ebelaker from:  F. A. MacNutt, Bartolomew de las Casas:  His Life, His Apostulate and His Writings, 1909; A. L. Kroeber, "Cultural and Natural Areas of Native North America, University of California Publications in American Archeology and Ethnology, 1939.)

     Ubelaker gives a table showing 22 sets of estimates made between 1910 and 1988.  As he points out, the table is made difficult to interpret not only because of conflicting methodologies, but also by different definitions of the geographic areas involved, and different dates for which the estimates are proposed to hold.  Ubelaker says:  "For example, most scholars define North America as north of Mexico or north of the Rio Grande; however for Dobyns (1983), the area is 'north of civilized MesoAmerica'.  I [Ubelaker] have followed the usage of the Handbook of North Americl Indians in defining it as 'north of the urban civilizations of central Mexico."  One estimate in the table is offered for the years 1200 A.D.  Another focuses on the middle of the 17th century, another on the early years of the 16th century.  One refers to the "moment of discovery."  Presumably 1492 is meant, but Ubelaker points out that: "In reality there were many individual 'moments of discovery' as European contact with American Indian groups gradually moved from east to west."

     The estimates shown in Ubelaker's table for North America (as defined by him) vary from 900,000 (A. L. Kroeber, 1939) to 18,000,000 (H. F. Dobyns in Their Number Become Thinned:  Native American Population Dynamics in Eastern North America, 1983.)  For the total number of Indians in the whole Western Hemisphere, the estimates very from 8,400,000 (A. L. Kroeber, 1939) to 100,000,000 (W. Borah, "America as Model:  The Demographic Impact of European Expansion upon the Non-European World," 35th Congreso Internacional de Americanistas, Actas y Memorias, 1964.)  In 1924, K. Sapper estimated 2,000,000 to 3,000,000 in the United States, 2,500,000 to 3,500,000 in North America, and 40,000,000 to 50,000,000 in the Western Hemisphere ("Die Zahl und die Volksdichte der indianischen Bevolkerung in Amerika von der Conquista und in der Gegenwart," Proceedings of the 21st International Congress of Americanists, 1924).  In 1976, W. M. Denevan estimated 4,400,000 in North America and 43,000,000 to 72,000,000 in the Western Hemisphere ("Epilogue" in The Native Population of the Americas in 1492, edited by Denevan, 1976.)  In 1987, Russell Thornton e4stimated 5,000,000 in the United States, 7,000,000 in North America, and 72,000,000 in the Western Hemisphere (American Indian Holocaust and Survival:  Population History Since 1492, 1987).

     In The Invasion of America:  Indians, Colonialism, and the Cant of Conquest, published in 1975 before a number of the foregoing estimates were made, Francis Jennings made an extended critique and rejection of Alfred Kroeber's estimates cited above.  He traces Kroeber's figures back to the first estimates cited by Ubelaker, those of J. M. Mooney in 1910.  According to Ubelaker, who cites vol.2 of the Handbook of American Indians North of Mexico edited by F. W. Hodge, Bureau of American Ethnology Bulletin 30, these were 846,000 for the United States, and 1,148,000 for North America.  Jennings cites only 1,100,000 for North America.  He also says Mooney's figures were published posthumously in 1928 in The Aboriginal Population of America North of Mexico, edited by John W. Swanton, Smithsonian Miscellaneous Collections, LXXX, where Jennings may have got his figure.  Jennings says of Kroeber that "in his work on population, the words are before us and the characterization of Indian cultures are nonemmpirical and value laden, to the Indians' great prejudice," and also that Kroebers's writing "provides a convenient target for criticism, and it has been enormously influential because of his prestige as a world leader in anthropology, but his greatest significance for present purposes is his faithful echo of an enduring tradition."

     The tradition Jennings is referring to is one of discounting estimates of one's predecessors.  Jennings says:  "The same sort of procedure had been used by every generation of scholars since the original data were recorded in the seventeenth century [referring to an estimate for New England], and by Mooney's time discount upon discount had reduced the accepted figures to a small fraction of what was mentioned in the sources.  It is as if one were to estimate the population of white Americans in 1790 by successive slashes of the census data of that year on the grounds that the census takers were probably exaggerating their numbers for undisclosed reasons."

     Jennings concludes that estimate "must be very sharply revised upward from the limits given by Mooney and Kroeber."  He quotes Henry F. Dobyns, from an article "Estimating Aboriginal Population" in Current Anthropology, 1966, as giving a range of 10 to 12 million north of the Rio Grande, and 90 to 112 million for the Western Hemisphere.  In Ubelaker's table, Dobyns's figures for 1966 are given as 9,800,000 for North America and 90,043,000 for the Western Hemisphere.  Ubelaker cites the same article, although he gives the title as "Estimating Aboriginal American Population:  An Appraisal of Techniques with a New Hemispheric Estimate."  (Jennings cites p. 414, Ubelaker, pp. 395-416.)  As I indicated above, in his book Their Number Became Thinned (1983), Dobyns gives a later figure of "approximately 18 million Native Americans living north of civilized MesoAmerica in the early years of the sixteenth century."

     A set of estimates of American Indian populations in 1492 is given by Russell Thornton in American Indian Holocaust and Survival:  A Population History Since 1492 (1987).  These estimates are quoted in Ubelaker's table as 5,000,000 for the United States, 7,000,000 for North America, and 72,000,000 for the Western Hemisphere.  Actually, Thornton says in the book cited:  "The aboriginal population of the conterminous United States area was probably 5+ million when Columbus arrived in the Western Hemisphere in 1492.  Dobyns's methodology applied to the Canadian area yields a population estimate of 2+ million.  When smaller aboriginal populations for present-day Alaska and Greenland are added to these, we have a conservative total of 7+ million for the area north of Mexico."  Also he says:  "I assert that the aboriginal population of the Western Hemisphere circa 1492 is therefore close to the upper limit of H. J. Spinden's range [1928] of from 50 to 75 million for A. D. 1200."

     Thornton, like Ubelaker, describes the various ways that population data for Native Americans have been obtained.  Besides methods listed by Ubelaker (described above),Thornton calls attention to uses of ecological evidence.  He says:  "These are primarily estimates of how many people could have been supported in a given area at the level of technology used, sometimes referred to as the 'carrying capacity' of the environment."  Thornton observes that, as William M. Denevan noted, "this is an imprecise index, however, since both the environment and the technology are readily subject to change. ...  Also, just because a population could have been supported by the environment and technology, it does not mean that the actual population was that large."  In connection with checking data for accuracy, Thornton recommends using what he calls the abundant knowledge about populations which demographers have produced in the scientific study of human populations.  "We know," he says, "many characteristics of population structure and variables of population change, and we have mathematical and statistical equations to ascertain structure and change, given incomplete data."  Given some sufficiently reliable data, projections (or, in this case, retrojections) can be made by various methods, including curve-fitting based on mathematical and statistical formulas, using computers.

     In American Holocaust:  Columbus and the Conquest of the New World (1992), David Stannard gives some population sizes estimated by Carl Sauer, Sherburne F. Cook and Woodrow Borah and other members of the so-called "Berkeley School" (University of California) of historical demographic technique.  Stannard says:  "The results of these efforts were the most detailed and methodologically sophisticated population estimates ever conducted for the pre-European Americans.  And the figures they turned up were astonishing:  25,000,000 people for central Mexico alone and 8,000,000 people for Hispaniola are just two of the more striking re-calculations by members of the Berkeley School.  By the early 1960s the accumulated body of such studies was sufficient to allow Woodrow Borah to assert that the pre-Columbian population of the Americas was probably 'upwards of one hundred million'.  Soon after, anthropologist Henry F. Dobyns published a famous watershed analysis that had been conducted up to that time.  His conclusion was that North and South America contained between 90,000,000 and more than 112,000,000 people before the coming of the Spanish.  [Woodrow Borah, "America as Model:  The Demographic Impact of European Expansion Upon the Non-Western World," Actas y Memorias del XXXV Congreso Internacional de Americanistas, 1962; Henry F. Dobyns, "Estimating Aboriginal American Population:  An Appraisal of Techniques with a New Hemispheric Estimate," Current Anthropology (1966).]  Comparative figures for selected others of the world at this same time put the populations of Europe at 60,000,000 to 70,000,000; Russia at 10,000,000 to 18,000,000 and Africa at 40,000,000 to 72,000,000.  [John H. Durand, "Historical Estimates of World Population:  An Evaluation," Population and Development Review (1977).]"

     Russell Thornton in American Indian Holocaust and Survival:  A Population History Since 1492 (1987) says that the decline in American Indian populations from 1492 to 1890-1900 can be summarized as follows:  "I estimated ... a total population of 72+ million American Indians in the Western Hemisphere in 1492.  This 72+ million declined in a few centuries to perhaps only about 4 to 4.5 million. ... This was a population about 6 percent of its former size.  It represents a tremendous population decline over the centuries."  On this, Thornton refers to the article by Henry Dobyns cited above, and an article by himself and Joan Marsh-Thornton, "Estimating Prehistoric American Indian Population size for United States Area:  Implications of the Nineteenth Century Population Decline and Nadir," American Journal of Physical Anthropology (1981).

     Thornton goes on:  "I estimated ... that there were as many as 2+ American Indians north of the conterminous United States in 1492. ... This was a population about 7 percent its former size, indicating a decline of approximately 500,000 per century."  Sources:    U. S. Bureau of the Census, Report on Indians Taxed and Indians Not Taxed in the United States (except Alaska) at the Eleventh Census: 1890 (1894); U.S. Bureau of the Census, Indian Population of the United States and Alaska, 1910 (1915); James Mooney, "Population" in Handbook of Indians of Canada (1913), ed. Frederick W. Hodge; James Mooney, "The Aboriginal Population of America North of Mexico" in Smithsonian Miscellaneous Collections (1928), ed. John R. Swanton.

     According to Thornton:  "The 5+ million American Indians in the conterminous United States area, estimated [earlier], had declined to but 600,000 by 1800, the first date for which we have any reasonably good population data on American Indians of the United States.  They had declined further to about 250,000 by the last decade of the nineteenth century. ... This was a population some 4 to 5 percent of its former size, representing a population decline of approximately 1.25 million per century.  It was then between 1890 and 1900 that the American Indian population of North America reached its nadir.  It began to increase which continues today ..."

     Thornton cites the so-called fundamental demographic equation which says that population size at a time T2 equals its size at an earlier time T1 plus the differences between births and deaths and between immigration and emigration in the time interval between T1 and T2.  Thornton says:  "American Indian migrations into and out of the United States area were almost insignificant to population change, although a few happened, as shall be shown."  Therefore, Thornton says:  "The American Indian population in the United States area decreased from 5+ million in 1492 to about 250,000 in the decade from 1890 to 1900 because there were more American Indian deaths than births between 1492 and the end of the nineteenth century.  Such a population decline implies not only that some 5 million American Indians died during the 400 years but also that, in fact, many times the approximate figure of 5 million died, as new but ever numerically smaller generations of American Indians were born, lived, and died."

     Such a decline, as Thornton says, "may result from either higher death rates or lower birth rates, or some combination of changes in both.  The American Indian decline was due to both increases in death rates and decreases in birth rates, but it is clear that the increased death rates were of primary importance.  The various reasons for the increased American Indian death rates were interrelated, and some also caused lower birth rates and even migrations.  All of the reasons stemmed from european contact and colonization;  introduced disease, including alcoholism;  warfare and genocide;  geographical removal and relocation;  and destruction of ways of life."

     Thornton quotes James Mooney (article cited above) on the relative importance of these causes:  "The chief cause of decrease, in order of importance, may be classed as smallpox and other epidemics; tuberculosis; sexual diseases; whiskey and attendant dissipation; removals, starvation and subjection to unaccustomed conditions; low vitality due to mental depression under misfortune; wars.  In the category of destroyers, all but  wars and tuberculosis may be considered to have come from the white man, and the increasing destructiveness of tuberculosis itself is due largely to conditions consequent upon his advent."  Thornton says he has no particular quarrel with Mooney's ranking, but adds:  "I will show in detail, however, that genocide must be added to his list.  It would probably fall somewhere in the middle to lower part of the rankin.  It has been suggested that some depopulation was also due to diseases that American Indians shared with wild animals  such as the beaver and caribou. ... I doubt that such zoonoses were very important in the overall decline of the American Indian population."  For zoonoses, Thornton cites Calvin Martin, "Wildlife Diseases as a Factor in the Depopulation of the North American Indians", Western Historical Quarterly (1976).

     In American Holocaust:  Columbus and the Conquest of the New World (1992), David Stannard says:  "Just twenty-one yers after Columbus's first landing in the Caribbean, the vastly populous usland that the explorer had re-named Hispaniola was effective desolate:  nearly 8,000,000 people --- those Columbus chose to call Indians --- had been killed by violence, disease, and despair. ... And Hispaniola was only the beginning.  Within no more than a handful of generations following their first encounters with Europeans, the vast majority of the Western Hemisphere's native peoples had been exterminated."  Stannard has sections on the depopulation from 1492 through the 19th century of Arawaks of the West Indies, Aztecs of Mexico, Mayans of Central America, Incas of Peru and Chile, indigenous peoples of Brazil, Powhatans of Virginia, Pequots, Narragansetts, Mohicans, Mohawks and other tribes of New England and what became New York. Cherokees of what became the southeastern United States (later moved to Oklahoma) and others, culminating with the massacres at Sand Creek in 1864 and Wounded Knee in 1890.  His summary of Spanish activity from 1492 to 1600 reads:  "By the time the sixteenth century had ended perhaps 200,000 Spaniards had moved their lives to the Indies, to Mexico, to Central America, and points further south.  In contrast, by that time somewhere between 60,000,000 and 80,000,000 natives from those lands were dead."  Stannard describes a large number of what he calls population crashes of particular Indian groups, giving estimated numbers and percentages of populations.  He says:  "Take Illinois, for example.  Between the late seventeenth and late eighteenth centuries the number of Illinois Indians fell by about 96 percent ... That massive destruction was the result of war, disease, and despair --- despair in the face of apparently imminent extinction from a siege the likes of which cannot be imagined by those who have not endured it.  A fragmentary selection of examples from every corner of the continent --- in addition to the instances already discussed tells the same depressing tale over and over again."  Stannard then proceeds to give a long list of examples, based on a variety of studies made in the 1970s and 1980s.

     Stannard warns about how we treat disease as a factor in the kill-off of Native Americans:  "The extraordinary outpouring of recent scholarship that has analyzed the deadly impact of the Old World on the New has employed a novel array of research techniques to identify introduced disease as the primary cause of the Indians' great population decline.  As one of the pioneers in this research put it twenty years ago, the natives' 'most hideous' enemies were not the European invaders themselves,, 'but the invisible killers which those men brought in their blood and breath.'  [Alfred W. Crosby. Jr., The Columbian Exchange:  Biological and Cultural Consequences of 1492 (1972).]  It is true, in a plainly quantitative sense of body counting, that the barrage of disease unleashed by the Europeans among the so-called 'virgin-soil' populations of the Americas caused more deaths than any other single force of destruction.  However, by focusing almost entirely on disease, by displacing responsibility for the mass killing onto an army of invading microbes, contemporary authors increasingly have created the impression that the eradication of those tens of millions of people was inadvertent --- a sad, but both inevitable and 'unintended consequence' of human migration and progress.  [Stannard refers to articles by Martin Harris, "Depopulation and Cultural Evolution:  A Cultural Materialist Perspective" in Columbian Consequences, Volume Three:  Spanish Borderlands in Pan-American Perspective (1991) and by Alfred W. Crosby, "Infectious Disease and the Demography of the Atlantic Peoples," Journal of World History (1991).]  This is a modern version of what Alexander Saxton recently has described as the 'soft-side of anti-Indian racism' that emerged in America in the nineteenth century and that incorporated 'expressions of regret over the fate of Indians into narratives that traced the inevitability of their extinction.  Ideologically,' Saxton adds, 'the effect was to exonerate individuals, parties, nations, of any moral blame for what history had decreed.'  [Alexander Saxton, The Rise and Fall of the White Republic:  Class Politics and Mass Culture in Nineteenth-Century America (1991).]  In fact, however, the near-total destruction of the Western Hemisphere's native people was neither inadvertent nor inevitable.  ...  From almost the instant of first human contact between Europe and the Americas, firestorms of microbial pestilence and purposeful genocide began laying waste the American natives.  Although at times operating independently, for most of the long centuries of devastation that followed 1492, disease and genocide were interdependent forces acting dynamically --- whipsawing their victims between plague and violence, each one feeding upon the other. and together driving countless numbers of entire ancient societies to the brink --- and often over the brink --- of total extermination."

     Alfred W. Crosby asks in his book The Columbian Exchange:  Biological and Cultural Consequences of 1492 (1972):  "Why were the Europeans able to conquer America so easily?  In our formal histories and in our legends, we always emphasize the ferocity and stubbornness of the resistance of the Aztec, Sioux, Apaches, Tupinamba, Araucanian, and so on, but the really amazing thing about their resistance was its ineffectiveness, ,,, There are many explanations for the Europeans' success in America:  the advantage of steel over stone, of cannon and firearms over bows and arrows and slings; the terrorizing effect of horses on foot soldiers who have never seen such beasts before; the lack of unity among the Indians within their empires; the prophecies in Indian mythology about the arrival of white gods. ... Each factor was undoubtedly worth many hundreds of soldiers to Cortés and Pizarro and other great Indian-killers. ... For all of that, one might have at least expected the highly organized, militaristic societies of Mexico and the Andean highlands to survive the initial contact with the European societies.  Thousands of Indian warriors, even if confused and frightened and wielding only obsidian-studded war clubs, should have been able to repel the first few hundred Spaniards to arrive.  And what is the explanation for the fact that Indians were really only a little more successful in defending themselves and their lands after they learned that the invaders were not gods, after they obtained their own horses and guns and developed tactics to deal  with the Europeans?"

   Crosby quotes an Indian of Yucatan writing about the days before the Spanish conquest in The Book of Chilam Balam of Chumayel (translated by Ralph L. Toy, 1933):  "There was then no sickness; they had no aching bones; they had no high fever; they had then no smallpox; they had then no burning chest; they had then no abdominal pain; they had then no consumption; they had then no headache.  At that time the course of humanity was orderly.  The foreigners made it otherwise when they arrived here."   Crosby says:  "The impact of the smallpox pandemic on the Aztec and Incan Empires is easy for the twentieth-century reader to underestimate. ... Because of the achievements of modern medical science we find it hard to accept statements from the conquest period that the pandemic killed one-third to one-half of the populations struck by it.  Toribio Motolinía claimed that in most provinces of Mexico 'more than one half of the population died; in others the proportion was little less ... They died in heaps like bedbugs."  (From Molinía's History of the Indians of New Spain, translated by Elizabeth A. Foster, 1950; Molinía died in 1568.)

     "Migration of man and his maladies," says Crosby, "is the chief cause of epidemics. ... The fatal dieases of the Old World killed more effectively in the New, and the comparatively benign diseases of the Old World turned killer in the New. ... The most spectacular period of mortality among American Indians occurred during the first hundred years of contact with the Europeans and Africans. ... The victims of disease were probably greatest in number in the heavily populated highlands of New Spain (Mexico) and Peru, but, as a percentage of the resident population, were probably greatest in the hot, wet lowlands.  By the 1580s disease ably assisted by Spanish brutality, had killed off or driven away most of the peoples of the Antilles and the lowlands of New Spain, Peru, and the Caribbean littoral, 'the habitation of which coasts is ... so wasted and condemned, that of thirty parts of the people that inhabited it, there wants twenty nine; and it likely the rest of the Indians will in short time decay'."  (The quotation is said by Crosby to be from The Natural and Moral History of the Indies (no date), by Joseph de Acosta; this appears to be a translation of Historia natural y moral de las Indias  by José de Acosta, who lived c1539-1600.)

     Russell Thornton says in American Holocaust and Survival (1987):  "Of the diseases introduced from the Eastern Hemisphere the greatest early killers of American Indians were probably smallpox, strong strains of typhus, and measles; and smallpox was without doubt the leader of the three.  Tuberculosis, though probably not first brought here from the Eastern Hemisphere, likely heads the list of more recent killers of American Indians.  The destructiveness of alcoholism is surely not far behind, and it has been linked to the current high mortality rates of American Indians from suicide, accidents, diabetes, and, of course, cirrhosis. ... The diseases did not merely spread among Indians, kill them, and then disappear.  It has recently been calculated that there may have been aas many as 93 serious epidemics and pandemics of Old World pathogens among North American Indians from the early sixteenth century to the beginning of the twentieth century [Henry Dobyns, Their Numbers Become Thinned, 1983]."  In other words, Dobyns says that a "serious contagious disease causing significant mortality invaded Native American peoples at intervals of four years and two and a half months, on the average, from 1520 to 1900."

     On the other hand, Thornton says:  "While warfare and genocide were not very significant overall in the American Indian population decline, they were important causes of decline for particular tribes.  Some American Indian peoples were even brought to extinction or the brink of extinction by warfare and genocide or perhaps it is more accurate to say, by genocide in the name of war.  ...  The distinction between war and genocide is not well defined:  atrocities of American Indian genocide have been called war by non-Indians.  For example, the battle at Wounded Knee Creek in South Dakota, where several  hundred old men, women, and children were massacred, was not a battle:  it was genocide, as was the Sand Creek Massacre of some 150 Cheyenne (and what is happening today to American Indians in some of the countries of Central and South America). ...  We can only guess numbers of American Indians killed by genocide.  And it is undoubtedly more problematic to guess the losses from genocide because genocide was neither as well recorded nor as well publicized as warfare.  We do know that in Texas and California, particularly Northern California, there was blatant genocide of American Indians by non-Indians during certain historic periods."

     Thornton has two graphs in the preface to his book on population and depopulation of the Indians which compare the American Indian population decline and recovery with non-Indian population growth in the United States area for 1492-1980.  The graph for the Indians is shaped roughly like a parabola which starts with a height representing a population of 5+ million in 1492, then decreases, with a decreasing rate of decrease, to a minimum just before 1900 when the population size reached its nadir of under 240,000, then rises to about 1.4 million in 1980, and rises smoothly beyond there for a few years.  The graph for the non-Indian population starts at 0 in 1492 and grows to about 226.5 million in 1980.  (It looks like an exponential curve, which is no doubt a simplification, since it seems to require more than a single exponential curve to model U. S. population growth during this period.)