The Federal government requires a census to be taken once every ten years for the apportionment of members of the U.S. House of Representatives. Census records are the only records that describe the entire population of the United States on a particular day. The answers given to the census takers tell us, in detail, what the United States looked like when the census was taken, and what issues were most relevant to Americans after a decade of economic depression. The first census was taken in 1790. Over the years, the format of census schedules changed and more questions were asked.
The U.S. government will not release personally identifiable information about an individual to any other individual or agency until 72 years after it was collected for the decennial census. The US Census Bureau provides more information about census record availability.
A bit about census records:
For more information about what you'll find in census records, visit Census Records from the National Archives.
The records that appear in genealogy research sites like FamilySearch are entered by hand by people who have to decipher the handwriting on very old documents. This can lead to errors or inaccuracies and sometimes makes it difficult for you to find records.
Instead of searching the full last name, use a wildcard (*) to search just the first few letters.
For example, when Frank Starzak arrived to the United States in 1902, he was listed on the New York Passenger Arrival List as "Franciszek Starzak." On the 1920 census, he was listed as "Frank Stzarsek." To allow for alternate spellings of names, you might use wildcard searches that look like this: Fra* Star* or Fran* Starz* or Franc St*