The 1812–13 United States House of Representatives elections were held on various dates in various states between August 3, 1812 and April 30, 1813. Each state set its own date for its elections to the House of Representatives before the first session of the 13th United States Congress convened on May 24, 1813. They coincided with James Madison being re-elected president. With the addition of the new state of Louisiana's at-large seat, along with the 39-seat gain as a result of the congressional reapportionment based on the 1810 United States Census, the size of the House increased to 182 seats. Most relative population growth was in the West. After America's entry into the War of 1812 against Britain, the Democratic-Republican and Federalist parties maintained pro-war and anti-war positions, respectively. Democratic-Republican representatives supported by voters in agrarian regions and Southern and Western states promoted war, asserting that Britain had violated American sovereignty and that despite Britain's strength, war was a manageable risk. Federalists and their supporters in New England and more densely populated Eastern districts opposed the war, citing likely damage to American trade and infrastructure. This election saw significant voter support shift to the declining Federalists for the last time, almost entirely in New England, New York, and New Jersey. Despite this shift, Federalists did not approach national political recovery, House control, or meaningful policy influence. Election summaries Following the 1810 census, the House was reapportioned, adding 39 new seats. Special elections There were special elections in 1812 and 1813 to the 12th United States Congress and 13th United States Congress. Special elections are sorted by date then district. 12th Congress |- ! | Barzillai Gannett | | Democratic-Republican | 1808 | | Incumbent resigned in 1812.New member elected April 6, 1812.Democratic-Republican hold.Successor seated June 3, 1812.Successor later lost re-election, see below. | nowrap | |- ! | Howell Cobb | | Democratic-Republican | 1806 | | Incumbent resigned before October 1812 to accept a captain's commission in the U.S. Army.New member elected October 5, 1812.Democratic-Republican hold.Successor seated November 27, 1812.Successor also elected the same day to the next term, see below. | nowrap | |- ! | Robert L. Livingston | | Federalist | 1808 | | Incumbent resigned to accept commission as a lieutenant colonel.New member elected December 15–17, 1812.Federalist hold.Successor seated January 29, 1813.Successor also elected the same day to the next term, see below. | nowrap