This database estimates total resident population on July 1st of each year for the United States, states, counties, and places (also known as cities or towns). The benchmark for population estimates is the 2000 Census of Population and Housing. 

We report data for cities and places based on the Census Bureau's intercensal method for 1990-1999.  In all other cases, we rely on postcensal data.   As a result, there may be substantial differences in cities and places population between 1999 and 2000.  For more information on how these estimates are generated, see Population Estimates Background or see Census methodology.