The Twentieth 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, 1827, to March 4, 1829, during the third and fourth years of John Quincy Adams's presidency. The apportionment of seats in the House of Representatives was based on the Fourth Census of the United States in 1820. Both chambers had a Jacksonian majority.
Elections to the United States House of Representatives for the 20th Congress were held at various dates in each state in 1826 and 1827 during John Quincy Adams' term in office.
Elections to the United States House of Representatives for the 19th Congress coincided with the contentious presidential election of that year. While the bulk of states held their elections in 1824, six states scheduled their general elections at various times during 1825.
The 1827 United States Senate election in New York was held on February 6, 1827, by the New York State Legislature to elect a U.S. Senator to represent the State of New York in the United States Senate.
The 1829 United States Senate special election in New York was held on January 15, 1829, by the New York State Legislature to elect a U.S. Senator to represent the State of New York in the United States Senate.
The United States Senate elections of 1858 and 1859 were elections which had the Republican Party gain five additional seats in the United States Senate, but the Democrats retained their majority. That majority would erode in 1860 with the secession of the southern states leading up to the Civil War. In Illinois, incumbent Stephen A. Douglas (D) and challenger Abraham Lincoln (R) held a series of seven debates, known as the "Lincoln–Douglas debates."
In the United States Senate elections of 1870 and 1871, the Republican Party lost five seats in the United States Senate, though it still retained an overwhelming majority. In advance of these elections, the last four seceded states were readmitted to the Senate.
The United States Senate elections of 1880 and 1881 were elections that coincided with the presidential election of 1880, and had the Democratic Party lose five seats in the United States Senate. The newly elected Readjuster senator caucused with the Republicans, and the Republican Vice President's tie-breaking vote gave the Republicans the slightest majority. All of that changed September 19, 1881 when the Vice President ascended to the Presidency and the Senate became evenly-divided.
The United States Senate elections of 1906 and 1907 were elections which had the Republican Party gain three seats in the United States Senate, expanding their majority to more twice that of the opposing Democratic Party.
The United States Senate elections of 1840 and 1841 were elections which, corresponding with their Party's success in the 1840 presidential election, had the Whig Party take control of the United States Senate.
The United States Senate elections of 1838 and 1839 were elections which had the Democratic Party lose seven seats in the United States Senate, but still retain a majority.
The United States Senate elections of 1836 and 1837 were elections that had the Jacksonian coalition emerge as the Democratic Party, and the Adams, or Anti-Jackson, coalition emerge as the Whig Party
The United States Senate elections of 1834 and 1835 were elections that had the Anti-Jackson coalition maintain control of the United States Senate. However, during the 24th Congress, the Jacksonian coalition gained control of the Senate.
The United States Senate elections of 1832 and 1833 were elections that had the Anti-Jackson coalition assume control of the United States Senate from the Jacksonian coalition, despite Andrew Jackson's victory in the presidential election.
The United States Senate elections of 1830 and 1831 were elections that had Jacksonians gain one seat in the United States Senate from the Anti-Jacksonian coalition, but lose one seat to the short-lived Nullifier Party. By the time Congress first met in December 1831, however, the Jacksonians had a net loss of one seat.
In the United States Senate elections of 1828 and 1829, the Jacksonian coalition, despite its leader's victory in the presidential election, lost a seat in the Senate to the opposing Anti-Jacksonian coalition.
The United States Senate elections of 1822 and 1823 were elections for the United States Senate that had the Democratic-Republican Party continue almost complete control of the Senate.
The United States Senate elections of 1824 and 1825 were elections for the United States Senate that saw the Jacksonians gain a majority over the Anti-Jacksonian National Republican Party.
The 1826 United States elections occurred in the middle of Democratic-Republican President John Quincy Adams's term. Members of the 20th United States Congress were chosen in this election. The election took place during a transitional period between the First Party System and the Second Party System. With the Federalist Party no longer active as a major political party, the major split in Congress was between supporters of Adams and supporters of Andrew Jackson, who Adams had defeated in the 1824 Presidential election.
