This study was conducted under the auspices of the Center for Studies in Demography and Ecology at the University of Washington. It is a nationally representative sample of the population of the United States in 1900, drawn from the manuscript returns of individuals enumerated in the 1900 United States Census. Household variables include region, state and county of household, size of household, and type and ownership of dwelling. Individual variables for each household member include relationship to head of household, race, sex, age, marital status, number of children, and birthplace. Immigration variables include parents' birthplace, year of immigration and number of years in the United States. Occupation variables include occupation, coded by both the 1900 and 1950 systems, and number of months unemployed. Education variables include number of months in school, whether respondents could read or write a language, and whether they spoke English.

This nationally representative sample of the United States population in 1910 was drawn from manuscript census schedules. The file contains a record for each household selected in the sample, and supplies variables describing the location, type, and composition of the households. Each household record is followed by a record for each individual residing in the household. Information on individuals includes demographic characteristics, occupation, literacy, nativity, ethnicity, and fertility.