High Quality Content by WIKIPEDIA articles! The Eightieth United States Congress was a meeting of the legislative branch of the United States federal government, composed of the United States Senate and the United States House of Representatives. It met in Washington, DC from January 3, 1947 to January 3, 1949, during the third and fourth years of Harry S. Truman`s presidency. The apportionment of seats in this House of Representatives was based on the Sixteenth Census of the United States in 1940. Republicans gained a majority in both chambers for this Congress. The Democrats had the majorities in the previous Congress and they regained them back in the next Congress.