The 27th 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., between March 4, 1841, and March 4, 1843, during the one-month presidency of William Henry Harrison and the first two years of the presidency of his successor, John Tyler. The apportionment of seats in the House of Representatives was based on the 1830 United States census. Both chambers had a Whig majority, making the 27th Congress the only Whig-controlled Congress of the Second Party System.

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 1830 United States census. Both chambers had a Democratic majority.