The 21st United States Congress was a meeting of the legislative branch of the United States federal government, consisting of the United States Senate and the United States House of Representatives. It met in Washington, D.C. from March 4, 1829, to March 4, 1831, during the first two years of Andrew Jackson's presidency. The apportionment of seats in the House of Representatives was based on the Fourth Census of the United States in 1820. Both chambers had a Jacksonian majority.