Census Records and Immigration
Once you've found the country from which your ancestors emigrated, the next step is to confirm the information provided in the immigration documents to ensure accuracy. This can be done by comparing names, dates, and vital information with other records. U.S. federal census records can be particularly useful to help you verify these details.

1820 - Asked for number of persons in household not naturalized.

1850 - Asked for details on all members of the household and records specific country or territory of birth.

1870 - Indicated if parents are of foreign birth. Also identified immigrants who were naturalized and eligible to vote. Indications of a person's color were also more precise (rather than just "white" or "colored"). This can be helpful in determining an individual's origins.

1880 - Stated the relationship of household members to head of household.

1900 - Listed the year of immigration, the number of years in the United States, and the citizenship status of foreign-born individuals over age twenty-one.

1910 - Listed parent's birthplaces and native language. The Indian schedule also recorded an individual's tribe and/or band.

1920 - Listed specific details about citizenship: whether or not they were naturalized or alien; if naturalized, year of naturalization; birth country and native language of the person; native language and birthplace of the individual's parents; native language of the individual's grandmothers. Also enumerated Guam, American Samoa, the Panama Canal Zone, and the Virgin Islands.

1930 - Listed year of immigration, naturalization, and the language spoken in the home before coming to the U.S.