The Republican Party was a political party active in the United States between 1854 and 1938. Nine US Presidents were members of the Republican Party. The party dominated the Third and Fourth Party systems.The Party was formed in the mid 1850's by anti-slavery activists, and between 1860 to 1912 Republican Presidential candidates won all but two elections (1884 and 1892).
Their main voter base was a coalition of northern white protestants, businessmen, small business owners, the middle classes, factory workers, farmers and African-Americans. It emphasised pro-business economic policies, industrialization and modernization. Under William McKinley and Theodore Roosevelt the Republican party emphasised an expansive foreign policy.
During the Presidency of William Howard Taft the Republican Party began to split between pro-business conservatives such as Taft, Nicholas Murray Butler, Warren Harding and Elihu Root, and Progressives led by Theodore Roosevelt. When Roosevelt failed to obtain the Republican nomination in 1912 he left the party, forming the Progressive Party. In the election the Republicans came an embarrassing third, obtaining only 20% of the popular vote carrying only four states.