how many people have every lived in the U.S.?

Factual Questions
1

I guess if we just include those parts of N.America that have been states, territories, etc. and start with the founding of the nation, how many people have lived in the U.S. in total?

2

If a general number is fine, it looks like the population of the US has on average grown about 130% per every 20 years, So assuming that there is a new generation every 20 years and that there are three generations alive at any given period of time:


In millions

	total	gen1	gen2	gen3
2010	310	131	101	78
1990	238	101	78	60
1970	183	78	60	46
1950	141	60	46	35
1930	108	46	35	27
1910	83	35	27	21
1890	64	27	21	16
1870	49	21	16	12
1850	38	16	12	10
1830	29	12	10	7
1810	22	10	7	6
1790	17	7	6	4

So if we add all of gen1 from 1790 to 2010 plus gen2 and gen3 from 1790, we should have an estimate: 554 million people.

Note that I am by no means a mathematician, so this might have a tremendous number of errors. Also note that even if I’m right, the 130% growth figure doesn’t track quite right with the actual numbers (http://www.census.gov/population/censusdata/table-4.pdf PDF)

3

Thanks.