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.
History of the United States Republican Party
From 1939 through 1941, there was a sharp debate within the GOP about support for Britain in World War II. Internationalists, such as Henry Stimson and Frank Knox, wanted to support Britain and isolationists, such as Robert A. Taft and Arthur Vandenberg, strongly opposed these moves as unwise, if not unconstitutional. The America First movement was a bipartisan coalition of isolationists. In 1940, a total unknown Wendell Willkie at the last minute won over the party, the delegates and was nominated. He crusaded against the inefficiencies of the New Deal and Roosevelt's break with the strong tradition against a third term.