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.
United States
The United States has operated under a two-party system for most of its history. For elective offices at most levels, state-administered primary elections choose the major party nominees for subsequent general elections. Since the general election of 1856, the major parties have been the Democratic Party, founded in 1824, and the Republican Party, founded in 1854. Since the Civil War, only one third-party presidential candidate—former president Theodore Roosevelt, running as a Progressive in 1912—has won as much as 20% of the popular vote. The President and Vice-president are elected through the Electoral College system.