The 1830 United States census, the fifth census undertaken in the United States, was conducted on June 1, 1830.

The 1830 census asked these questions:[1] No microdata from the 1830 population census are available, but aggregate data for small areas, together with compatible cartographic boundary files, can be downloaded from the National Historical Geographic Information System.

Apportionment Populations[5] In the U.S. Constitution, Article 1, Section 2, Clause 3 states: Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons.

[6]In order to correctly apportion Representatives pursuant to this Census, it was necessary for the Census to compute not only the total population of each state, but the number of free persons and slaves, and then to compute the apportionment population, or Federal number, for each state (and territory) by adding three-fifths of the slave population to the free population.

(This was computed by county, so the totals for each state may be off by as many as 1.2 persons due to rounding.)