English: National Origins of the White Population of the United States in 1920, computed for apportionment of annual immigration quotas according to National Origins Formula, as prescribed by §11(c) of the Immigration Act of 1924. The U.S. Departments of State, Commerce, and Labor collaborated with the Census Bureau to study and classify national origins by birth or ancestry of all White Americans except those having origins in the nonquota countries of the Western Hemisphere (viz. Canada, Mexico, the Caribbean, Central and South America). To compute the proportions of blood each national origin had contributed to the American population as of the 1920 Census, demographers broke down the population into 4 more easily classifiable groups: immigrants (by land of foreign-birth), children of immigrants (by land of foreign parentage), descendants of colonial stock (of same ethnic proportional makeup as population enumerated in first U.S. Census in 1790), grandchildren and later generations of post-colonial immigrants (deduced working backward using past records of immigration and naturalization: persons of foreign-birth, parentage, or mother tongue in Census counts of 1920 and 1910; foreign-birth or parentage in Census counts of 1900 and 1890; foreign-born in Census counts of 1880, 1870, 1860, 1850; records of immigrants admitted in 1840, 1830, 1820).