The Republican Party was never a third party. Their first presidential candidate in 1856 won 114 electoral votes. The third place candidate was the Know Nothing nominee, Millard Fillmore, who won 8 or something like that.
1860 was a GOP route, and in 1864, Reublicans elected something like 200 members of Congress.
The republicans were a third party in 1856, they had only just formed in 1854.
The republican party was THE third party that gave us the term.
Many whigs jumped ship to join the third party as republicans, including Abe Lincoln.
History has facts.....
What was "third" about them?
from wiki;
Creation
See also: Third Party System
The Little White Schoolhouse in Ripon, Wisconsin, where the Republican Party was first organized locally in 1854
The Republican Party was first organized in 1854, growing out of the "anti-Nebraska" coalition of old Whigs, freesoil Democrats etc. who mobilized in opposition to Stephen Douglas's January 1854 introduction of the Kansas-Nebraska Act into Congress, a bill which repealed the 1820 Missouri compromise prohibition on slavery north of latitude 36° 30' in the old Louisiana purchase territories, and so was viewed as an aggressive expansionist pro-slavery maneuver by many. Besides opposition to slavery, the new party put forward a progressive vision of modernizing the United States—emphasizing higher education, banking, railroads, industry and cities, while promising free homesteads to farmers. They vigorously argued that free-market labor was superior to slavery and the very foundation of civic virtue and true American values—this is the "Free Soil, Free Labor, Free Men" ideology explored by historian Eric Foner.[1] The Republicans absorbed the previous traditions of its members, most of whom had been Whigs, such as Alvan E. Bovay and Horace Greeley; others had been Democrats or members of third parties (especially the Free Soil Party and the American Party or Know Nothings). Many Democrats who joined up were rewarded with governorships: (Nathaniel P. Banks of Massachusetts, Kinsley Bingham of Michigan, William H. Bissell of Illinois, Salmon P. Chase of Ohio, Hannibal Hamlin of Maine, Samuel J. Kirkwood of Iowa, Ralph Metcalf of New Hampshire, Lot Morrill of Maine, and Alexander Randall of Wisconsin) or seats in the U.S. Senate (Bingham and Hamlin, as well as James R. Doolittle of Wisconsin, John P. Hale of New Hampshire, Preston King of New York, Lyman Trumbull of Illinois, and David Wilmot of Pennsylvania.) Since its inception, its chief opposition has been the Democratic Party, but the amount of flow back and forth of prominent politicians between the two parties was quite high from 1854 to 1896.
Two small cities of the Yankee diaspora, Ripon, Wisconsin and Jackson, Michigan, claim to be the birthplace of the Republican Party (in other words, meetings held there were some of the first 1854 anti-Nebraska assemblies to call themselves by the name "Republican"). Ripon held the first county convention on March 20, 1854. Jackson held the first statewide convention where delegates including Abraham Lincoln from Illinois July 6, 1854 declared their new party opposed to the expansion of slavery into new territories and selected a state-wide slate of candidates. The Midwest took the lead in forming state party tickets, while the eastern states lagged a year or so. There were no efforts to organize the party in the South, apart from a few areas adjacent to free states. The party initially had its base in the Northeast and Midwest. The party launched its first national convention in Pittsburgh, Pennsylvania, in February 1856, with its first national nominating convention held in the summer in Philadelphia, Pennsylvania.[2]
This caricature tries to link Frémont to other "weird" movements like temperance, feminists, socialism, free love, Catholicism and abolitionism.
John C. Frémont ran as the first Republican nominee for President in 1856, using the political slogan: "Free soil, free labor, free speech, free men, Frémont." Although Frémont's bid was unsuccessful, the party showed a strong base. It dominated in New England, New York and the northern Midwest, and had a strong presence in the rest of the North. It had almost no support in the South, where it was roundly denounced in 1856-60 as a divisive force that threatened civil war.
entire article;
History of the United States Republican Party - Wikipedia, the free encyclopedia