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.
Heather Cox Richardson
In her latest book, "To Make Men Free: A History of the Republican Party" (2014), Richardson extended her study of the Republican Party into the twentieth and twenty-first centuries. This book studied the entire life of the GOP, from its inception in the 1850s through the presidency of George W. Bush. The party’s founders united against the “slave power,” a small group of wealthy white men who controlled all three branches of government. These Republicans articulated a new vision of an America in which all hardworking men could rise. But after the Civil War, Republicans began to emulate what they originally opposed. They tied themselves to powerful bankers and industrialists, sacrificing the well-being of ordinary Americans. A similar process took place after World War II, when Republicans sought to dismantle successful New Deal policies and prop up the wealthy. However, in both cases, reformers within the party were able to return the GOP to its founding vision of equality of opportunity, first Theodore Roosevelt during the Progressive Era, and then Dwight D. Eisenhower, who enforced integration and maintained the New Deal. The Nixon and Reagan administrations have represented yet another fall from the GOP’s founding purpose. It's ironic, Richardson points out, that Republicans treated Barack Obama with an unprecedented level of disrespect, as Obama's rise from humble beginnings to the highest office in the nation embodied the vision of the original Republicans.