(1) Generations back from 2000

(2) The number of ancestors (Great-Great-... Grandparents, ...) for people in generation 1 (born around 2000) assuming the number doubles each generation. People point out that after about 30 generations the number of a persons ancestors exceeds the world population. The fallacy in this argument is that prior to 100 years ago a lot of people married 2nd and 3rd cousins, so lines tend to merge as you move back.

(4) People who reported race as American Indian in the US census increased 70% from the 1970 to the 1980 census to about 1.4 M. Less than half can be explained by birth rates. Most seems to be due to people changing their racial identification. The 2000 census allowed people to report mixed races. Indians increased from 2 M in 1990 to 4.1M in 2000. The 4.1 M included 1.6 M who were mixed race and 2.5 who were 100%.

See Also: World Population

* Native Americans. Native Americans (Indians) were initially not included in Census data. The Native American population in the South Eastern US alone was about 95,000 in 1650.
The Native American population in California was about 300,000 when the Spanish arrived in 1769, but was reduced to 150,000 by 1834.

Mooney, James. Manuscript published posthumously in 1928 estimated 1,152,000 in North America (USA, Alaska, Canada & N. Mexico) at the time white men came

Ubelaker, Douglas. "North American Indian Population Size, A.D. 1500 to 1985." American Journal of Physical Anthropology 77 (1988):289-294. An update of his "The Sources and Methodology of Mooney's 1928 Estimates of North American Indian Populations" Estimates 1,894,350 in 1500 and 530,000 by 1900 in North America.

Other estimates: Kroeber (1939)- 900,000; Dobyn (1966) - 9,800,000

Alison Wangsness Clement states in Rewriting American History: Does the Grade School American History Curriculum Reflect the Native American Experience? , 1997 that:

One of the fiercest scholarly battles to rage over the colonization of the Americas is over population estimates. For centuries, historians have underestimated the number of Native Americans that lived in the Americas in 1492.

Walter Prescott Webb erroneously estimated that the Indian population in what is presently the United States did not exceed 500,000 (Jennings 83).

Ronald Wright addresses these figures in his book Stolen Continents:
It is impossible to say exactly how many people were living in what is now the United States and Canada in 1492. But it's clear that the old guess of around 1 million is absurdly low-a guess cherished for so long because it reinforced the myth of the empty land and hid the enormity of Native America's depopulation. Good modern estimates range between 7 and 18 million. (123)

The great death raged for more than a century. By 1600, after some 20 waves of pestilence had swept through the Americas [North and South], less than a tenth of the original population remained. Perhaps 90 million died, the equivalent, in today's terms, to the loss of a billion. It was the greatest mortality in history. (Wright (11))

The American Nation says, "Scholars estimate that between 50 percent and 90 percent of Native Americans died of diseases introduced from Europe" (69). America Will Be says, "By 1650, smallpox had killed three-fourths of the Indians who once lived in North and South America" (122)

Today, few serious students of the subject would put the hemispheric figure at less than 75,000,000 to 100,000,000(with approximately 8,000,000 to 12,000,000 north of Mexico), while one of the most well-regarded specialists in the field recently has suggested that a more accurate estimate would be around 145,000,000 for the hemisphere as a whole and about 18,000,000 for the area north of Mexico.

The first Europeans to inhabit California were the Spanish who started building Missions in 1769. John Sutter got a land grant from the Spanish in 1939 and built a fort in Sacramento in 1941. The first settlers from the eastern US came in 1841, but the great migration was in -49 after gold was discovered at Sutter and Marshal's Mill. See History of Transportation & Communications to California.

1/ "Starting in 1960, includes population of Alaska and Hawaii. For 1890, excludes population enumerated in the Indian Territory and on Indian reservations for whom information on most topics, including nativity, was not collected. See Table 6."
3/ "The data shown in Table 1 are based on the 15-percent sample. For 1970, data based on the 5-percent sample show total population as 203,193,774, native population as 193,590,856, born in the United States as 191,836,655, born abroad as 1,617,396, in outlying areas as 873,241, of American parents as 744,155, and foreign-born population as 9,739,723. See text for Table 1."
4/ "In 1850 and 1860, information on nativity was not collected for slaves. The data in the table assume, as was done in 1870 census reports, that all slaves in 1850 and 1860 were native. Of the total Black population of 4,880,009 in 1870, 9,645, or 0.2 percent, were foreign-born (1870 census, Vol. I, Dubester #45, Table XXII, pp. 606-615)." Plagues - Famine The world population has decreased several times because of plagues and famine:

See Also: 2000 Census,
UN Population Information
Population Growth