Massachusetts Republican Party
The Massachusetts Republican Party was founded in 1854. Drawing together abolitionist and nativist anti-Catholic elements, it quickly became the dominant political force in the state and a powerful arm of the national Republican Party. Significant founding figures include Senator Charles Sumner, formerly of the Free Soil Party, and Speaker of the House Nathaniel Prentiss Banks, formerly of the American Party. 
At the time of the Republican Party's founding in 1854, all of Massachusetts's congressional representatives but Sumner were members of the nativist Know-Nothing Party. However, Banks's role as chairman of the 1856 Republican National Convention, his active support for the Republican presidential nominee John C. Frémont in 1856 and his focus on anti-slavery legislation as Speaker put him at odds with his party. Following the Democratic victory in the 1856 elections and the Dred Scott case in 1857, the national American Party organization collapsed, and most Northern members joined the nascent Republicans. In 1857, Banks ran as a Republican against incumbent Know-Nothing Governor Henry J. Gardner and won a decisive victory.
Party divisions of United States Congresses
Party divisions of United States Congresses have played a central role in 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. Political parties had not been anticipated when the U.S. Constitution was drafted in 1787, nor did they exist at the time the first Senate elections and House elections occurred in 1788 and 1789. Organized political parties developed in the U.S. in the 1790s, but political factions—from which organized parties evolved—began to appear almost immediately after the 1st Congress convened. Those who supported the Washington administration were referred to as "pro-administration" and would eventually form the Federalist Party, while those in opposition joined the emerging Democratic-Republican Party.