Party divisions of United States Congresses

Party divisions of United States Congresses have played a central role on the organization and operations of both chambers of the United States Congress—the Senate and the House of Representatives—since its establishment as the bicameral legislature of the Federal government of the United States in 1789.

Those who supported the Washington administration were referred to as "pro-administration" & would eventually form the Federalist Party, while those in opposition joined the emerging Democratic-Republican Party.

The following table lists the party divisions for each United States Congress.

Note that numbers in boldface denote the majority party at that particular time while italicized numbers signify a Congress in which the majority party changed intra-term.

This table shows the number of Congresses in which a party controlled either the House, the Senate, or the presidency.