The 26th 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, 1839, to March 4, 1841, during the third and fourth years of Martin Van Buren's presidency. The apportionment of seats in the House of Representatives was based on the Fifth Census of the United States in 1830. Both chambers had a Democratic majority.