Overview

The 1820 United States census was the fourth decennial enumeration of the population of the United States. Completed on August 7, 1820, it reported a total population of 9,638,453, of which 1,538,022 were recorded as enslaved. The census continued the early republic's effort to document inhabitants for representation and federal planning.

Scope and method

Enumeration was performed by federal marshals and local assistants who recorded households according to the law in force at the time. Returns covered the states and organized territories existing in 1820 and used separate columns to tally categories of residents. Enumerators recorded counts by sex and by broad age groups for free white persons and provided separate totals for other free persons and for slaves.

Key results and categories

The published summary emphasized total population, regional distributions and the number of enslaved people. Age-group breakdowns made the 1820 census useful for short-term demographic analysis, including the size of the young male population that influenced representation and conscription concerns in later decades.

Historical context and uses

The census occurred during a period of territorial growth and political change, the same year as the Missouri Compromise debates. Officials used census figures to apportion seats in the House of Representatives and to inform federal and state planning. Historians and demographers now rely on the 1820 totals to trace early national growth, migration patterns and the regional distribution of slavery.

Limitations and notable facts

  • Detail was less granular than modern censuses; many social and economic questions added later did not exist in 1820.
  • Because counts were recorded locally and returned to federal offices, the accuracy varied by district and distance from population centers.
  • The 1820 census is a key primary source for early U.S. population studies and is often cited in discussions of antebellum demographics and politics.

For a concise reference, this enumeration is commonly described simply as the fourth census of the nation and remains a foundation for understanding the United States' early nineteenth-century population.