Did Native Americans emigrate from the United States?

Compared to Canada or Mexico, the percentage of the US population identifying as Native American is lower, but, in the case of Canada, this is more due to higher rates of immigration into the US, rather than the demographics of Native Americans.

Mexican Native Americans had different demographic trends than those in either the USA or Canada, which is part of the reason why Native Americans are a much higher percentage of the population in Mexico. Much lower rates of immigration are another part of the reason.

The First Nations populations of Canada were severely reduced, largely by epidemic diseases, to a low point around 1900. In 1900 the First Nation population of Canada was 127,000, or about 2% of a total population of 5,300,000 (of which 5.1m European, 23,000 Asian, 17,000 African, and 127,000 Indigenous).

http://www.chrc-ccdp.ca/en/getBriefed/1900/population.asp

Since 1900, with the arrival of modern medicine, the Aboriginal population of Canada has grown to 1.4 million, and now makes up 4.3% of the population of Canada.

The demographics of American Indian populations in the USA are similar. Aboriginal populations in what would become the USA in 1500 are variously estimated at between 850,000 and 5m.

http://www.ewi-ssl.pitt.edu/econ/files/courses/110103_misc_nativeamericanpopulationgraphs.pdf

By the time of the first US census (in 1800) the Native American population (in a smaller area than today’s USA, and of dubious accuracy) was enumerated as 600,000. The low point in American Indian population was 1890 at 228,000 (0.4% of the total population of 63m at the time) (Alaskan Natives were included in the “American Indian” category in the 1890 census).

The low point of the American Indian population in the USA was 1890. Although American Indian populations began to recover after 1890, the American Indian percentage of the population did not start to grow until after 1950, as the non-Indian population (largely through immigration) grew as fast or faster than the Indian population. Since 1950, the American Indian share of the population has grown.

By 2010, in the USA, the American Indian and Alaska Native population only identified as such, was 2.9m (0.9% of the population), while those identifying as American Indian or Alaska Native in combination with one or more other groups in the USA was 2.3 million (0.7% of the population). Those identifying as totally or partially American Indian or Alaska Native made up about 1.7% of the population. Between 2000 and 2010, the population of American Indians and Alaska Natives was growing twice as fast as the growth rate of the overall US population, so their percentage of the population is gradually increasing.

http://www.census.gov/prod/cen2010/briefs/c2010br-10.pdf

So, in both the USA and Canada, Native American populations were devastated by recurring epidemic diseases to which they had little immunity. In both countries populations reached a low point about 1900. In both countries, populations have been recovering strongly since then. (In both countries, Native American populations have increased more than tenfold since the demographic low point.)

At the population low point, there were still almost twice as many Native Americans in the USA as in Canada. In 2010 (about 110 years after the low point) there are slightly more than twice as many Native Americans in the USA as in Canada. (The population of Native Americans has been growing faster in the USA than in Canada).

The reason that Native Americans are a lower % of the population in the USA than in Canada is due to the demographics (especially immigration) of the non-Native American populations in those two countries, rather than the demographics of Native Americans.

Mexico is a different story.

In Mexico, Indigenous populations also got hammered in a demographic catastrophe by diseases arriving in the Colombian exchange. Estimates vary a lot, but it seems that the bottom of the demographic decline was in the mid 1600s, when the indigenous population in Mexico reached a low point of between 1.2m and 3.4m (down from pre-contact estimates between 5 and 25 m).

Denser Indigenous populations in Mexico may have enabled diseases to become endemic (by about 100 years after the Colombian exchange) instead of remaining epidemic (as they did in much less dense populations in Canada and the USA). Endemic diseases are still deadly, but do not cause such drastic population declines, as they tend to kill off children (the adults being largely survivors who have acquired immunity), and children are more rapidly replaced than adults.

http://www.hist.umn.edu/~rmccaa/mxpoprev/cambridg3.htm

As well as the demographic crash from diseases bottoming much earlier in Mexico (250 years earlier), the numbers of the non-indigenous population were much smaller. In 1650, it is estimated that there were 10,000 Mexicans of European descent, and 35,000 Mexicans of African descent. In addition, there were circa 600,000 Mexicans who were classified as “mestizo” (meaning of mixed Indigenous, European and or African descent) as well as the 1.2m to 3.4m (est.) remaining indigenous population.

With the Indigenous population of Mexico being a much higher proportion of the population at the trough of the demographic crisis, and a much higher rate of inter marriage between the populations, it is not surprising that Mexico should have a much higher percentage of Native Americans in the population today.

Emigration of native Americans from the USA, while it might have happened in sporadic instances, did not play any major part in the demographics of Native Americans in the Nation.