有移民。美国本土人口出生率是下降的，可是加上移民，人口一直都在上升。其实只要控制移民的质量和数量就可以，不必全面反移民

1800	5,236,631		33.3%
1810	7,239,881		38.3%
1820	9,638,453		33.1%
1830	12,866,020		33.5%
1840	17,069,453		32.7%
1850	23,191,876		35.9%
1860	31,443,321		35.6%
1870	38,558,371		22.6%
1880	49,371,340		28.0%
1890	62,979,766		27.6%
1900	76,212,168		21.0%
1910	92,228,531		21.0%
1920	106,021,568		15.0%
1930	123,202,660		16.2%
1940	132,165,129		7.3%
1950	151,325,798		14.5%
1960	179,323,175		18.5%
1970	203,211,926		13.3%
1980	226,545,805		11.5%
1990	248,709,873		9.8%
2000	281,421,906		13.2%
2010	308,745,538		9.7%
2020	331,449,281		7.4%