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
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.