The 12th 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, 1811, to March 4, 1813, during the third and fourth years of James Madison's presidency. The apportionment of seats in the House of Representatives was based on the 1800 United States census. Both chambers had a Democratic-Republican majority.
The 13th 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, 1813, to March 4, 1815, during the fifth and sixth years of James Madison's presidency. The apportionment of seats in the House of Representatives was based on the 1810 United States census. Both chambers had a Democratic-Republican majority. The first two sessions were held at the Capitol building while the third, convened after the Burning of Washington, took place in the First Patent Building.
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.
The 1812–13 United States Senate elections were held on various dates in various states, coinciding with President James Madison's re-election. As these U.S. Senate elections were prior to the ratification of the Seventeenth Amendment in 1913, senators were chosen by state legislatures. Senators were elected over a wide range of time throughout 1812 and 1813, and a seat may have been filled months late or remained vacant due to legislative deadlock. In these elections, terms were up for the senators in Class 3.
The 1812 United States House of Representatives elections in New York were held from December 15 to 17, 1812, to elect 27 U.S. Representatives to represent the State of New York in the United States House of Representatives of the 13th United States Congress. At the same time, a vacancy was filled in the 12th United States Congress.
Massachusetts gained three seats after the 1810 census, all of which were added to the District of Maine. Its elections were held November 5, 1812, but since Massachusetts law required a majority for election, which was not met in the 19th district, a second ballot was held there January 6, 1813.
The 1810 census revealed dramatic population growth in Ohio since 1800, resulting in its representation increasing from a single Representative to six, resulting in the State being broken up into 6 districts, abolishing the at-large district. Jeremiah Morrow (Democratic-Republican), who had served since Ohio achieved statehood in 1803, retired to run for U.S. Senator, so that all six seats were open. Its elections were held October 13, 1812.
New Hampshire gained one seat after the 1810 census. Its elections were held August 31, 1812.
Georgia gained two seats after the 1810 census.
Louisiana held its first United States House of Representatives elections following its April 1812 admission to the Union on September 28–30, 1812. A special election for a seat in the 12th Congress and a general election for a seat in the 13th Congress were held at the same time, and had nearly-identical results.
New Jersey kept its delegation at six seats but changed from electing its Representatives on a statewide general ticket to using three plural districts of two seats each. These districts were used only for the 1812 election, and the state returned to using a single at-large district in 1814. This was only the second time that New Jersey used districts.
Kentucky gained four seats after the 1810 census.
Maryland's apportionment was unchanged. It elected its members October 12, 1812.
North Carolina gained one representative as a result of the census of 1810. Its elections were held April 30, 1813, after the term began but before Congress's first meeting.
South Carolina gained one representative as a result of the 1810 census, increasing from 8 seats to 9. Its elections were held October 12–13, 1812.
Virginia gained one seat after the 1810 census, bringing its representation in the House of Representatives to 23 seats, the largest number Virginia would ever have. Virginia went from having the most representatives to having the second-most tied with Pennsylvania. New York, with its 27 seats, surpassed Virginia and remained the most populous state until the late 1960s.
Rhode Island's apportionment was unchanged. Its elections were held on August 25, 1812.
A special election was held in Massachusetts's 17th congressional district on April 6, 1812 to fill the vacancy left by the resignation of Barzillai Gannett (DR) who resigned sometime in 1812 without having served.
Delaware gained a seat after the 1810 census, and chose to elect both seats on a general ticket. The ten years between 1813 and 1823 were the only time when Delaware was represented by more than one Representative, and is one of only three states that have never been divided into districts.
The 1812 United States Senate election in Pennsylvania was held on December 8, 1812. Abner Lacock was elected by the Pennsylvania General Assembly to the United States Senate.