Only a few counties' records exist. State Historical Society. More current years are not yet public. The Canadian census is very similiar to the US census. However, in Canada, the religious affiliation was included.
Few indexes exist.
Microfilmed copies of all are available at the Family History Library. In most states until mid-1906, the county courts maintained the naturalization records. Across the country, each county was in charge of creating its own form and recording the information. About 1900 many counties added additional information about the applicant. In mid-1906 district courts were created, by federal law, in each state.