List of U.S. states and territories by historical population

This is a list of U.S. states and territories by historical population, as enumerated every decade by the United States Census. As required by the United States Constitution, a census has been conducted every 10 years since 1790. Although the decennial census collects a variety of information that has been used in demographic studies, marketing, and other enterprises, the purpose of the census as stated in the Constitution is to produce an "actual enumeration" of the number of persons in the states in order to calculate their Congressional apportionment.

As the United States has grown in area and population, new states have been formed out of U.S. territories or the division of existing states. The population figures provided here reflect modern state boundaries. Shaded areas of the tables indicate census years when a territory or the part of another state had not yet been admitted as a new state.^[a] Since 1920, the "total population" of the United States has been considered the population of all the States and the District of Columbia; territories and other possessions were counted as additional population.^[b] As of 2021^[update], five U.S. territories (American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands), along with the U.S. Minor Outlying Islands, are not included in the count of total U.S. population.
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