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.
Charles T. Gorham
Originally a Democrat and later a Whig, Gorham was one of the founders of the Republican party when it was organized in the mid-1850s. In 1855 he was appointed Major General and commander of one of three divisions in the state militia, and in 1859 he was elected to one term in the Michigan State Senate. Gorham used both positions to recruit, train, and reorganize the militia in anticipation of the Civil War. He was a Delegate to the Republican National Conventions of 1864 and 1868, and served as a Presidential elector from Michigan in 1868, casting votes for the ticket of Ulysses S. Grant and Schuyler Colfax.