United States Census data includes the dicennial (10 year) census and the American Community Survey (ACS). The ACS provides more frequent population estimates of one-year, three-year, and five-year ranges depending on the size of a community, with larger metro areas sampled more frequently and less populated areas sampled with a wider range of three year or five year spans. There are free and paid ways to explore the wealth of census data.
CU Libraries Census Guide