William H. Seward
The Republican Party had been founded in 1854, in reaction to the Kansas-Nebraska Act. Its anti-slavery stance was attractive to Seward, but he needed the Whig structure in New York to get re-elected. In September 1855, the New York Whig and Republican parties held simultaneous conventions that quickly merged into one. Seward was the most prominent figure to join the new party, and was spoken of as a possible presidential candidate in 1856. Weed, however, did not feel that the new party was strong enough on a national level to secure the presidency, and advised Seward to wait until 1860. When Seward's name was mentioned at the 1856 Republican National Convention, a huge ovation broke out. In the 1856 presidential election, the Democratic candidate, former Pennsylvania senator James Buchanan, defeated the Republican, former California senator John C. Frémont, and the Know Nothing candidate, former president Fillmore.
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.