The Eighty-sixth 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, D.C. from January 3, 1959 to January 3, 1961, during the last two years of the presidency of Dwight D. Eisenhower. The apportionment of seats in the House of Representatives was based on the Seventeenth Census of the United States in 1950. Both chambers had a Democratic majority. When Alaska and Hawaii were admitted as states in 1959, the membership of the House temporarily increased to 437 (seating one member from each of those newly admitted states and leaving the apportionment of the other 435 seats unchanged); it would remain at 437 until  reapportionment resulting from the 1960 census.