White Population of the United States in 1920 in numbers, then calculating the percentage share each nationality made up as a fraction of the total. The National Origins Formula derived quotas by calculating the equivalent proportion of each nationality out of a total pool of 150,000 annual quota immigrants. This formula was used until the Immigration and Nationality Act of 1952 adopted a simplified formula limiting each country to a quota of one-sixth of one percent of that nationality's 1920 population count, with a minimum quota of 100. The formula required classification of the national origins by birth or ancestry of all White Americans, except those having origins in the nonquota countries of the Western Hemisphere. The total White American population in 1920 was estimated at 94,820,915. Whites with origins in the Western Hemisphere were estimated at 5,314,357—approximately 4,085,000 from Canada and Newfoundland; 1,126,000 from Mexico; 66,000 from the West Indies; and 37,000 from Central and South America. This left the total relevant population for the quota calculation formula at 89,506,558. To compute the proportions of blood each national origin had contributed to the American population as of 1920, demographers divided the population into four more easily classifiable groups by generation. The process was complicated due to the more limited set of data recorded in the country's earlier decades compared to the increasingly detailed information published in later versions of the United States census. 49,182,158 were deemed to be of immigrant stock, accounting for 55% of the total, subdivided into three categories. The easiest to classify were the two most recently-arrived generations of immigrants, accounting for 1/3 of the 1920 total: 13.5% of the total: 12,071,282 immigrants classified by land of foreign-birth recorded in the 1920 Census 19.7% of the total: 17,620,676 children of immigrants classified by land of foreign-birth, foreign parentage, or foreign mother tongue in the 1920 or 1910 Census 21.8% of the total: 19,490,200 grandchildren and later generations of immigrants classified based on past records of immigration and naturalization: persons of foreign-birth, parentage, or mother tongue in the Census counts of 1920 and 1910; foreign-birth or parentage in 1900 and 1890; foreign-born in the Census counts of 1850-1880; and records of immigrants admitted 1820-1840. 45.0% of the total: 40,324,400 descendants of colonial stock, apportioned into the same ethnic proportional makeup as the population enumerated in the 1790 Census Colonial stock estimation Calculation of the colonial stock proved