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.
History of the United States Republican Party
The Republican Party had a progressive element, typified in the early 20th century by Theodore Roosevelt in the 1907–1912 period (Roosevelt was more conservative at other points), Senator Robert M. La Follette, Sr. and his sons in Wisconsin (from about 1900 to 1946) and western leaders such as Senator Hiram Johnson in California, Senator George W. Norris in Nebraska, Senator Bronson M. Cutting in New Mexico, Congresswoman Jeannette Rankin in Montana and Senator William Borah in Idaho. They were generally progressive in domestic policy, supported unions and supported much of the New Deal, but were isolationist in foreign policy. This element died out by the 1940s. Outside Congress, of the leaders who supported Theodore Roosevelt in 1912, most opposed the New Deal.