The newly formed Republican Party met for the first time nationally on February 22, 1856 in Pittsburgh, PA, to begin forming plans to oppose the Democrats’.
The Republican Party was formed by individuals who believed that the Federal government should not have passed the Kansas-Nebraska Act, and by those who wished to see a modernization of the United States, highlighting education, industry and free homesteads in the West for farmers. The first informal meeting took place in the small town of Ripon, WI, with a second meeting official meeting held in Jackson, MI. In 1854 at the state convention in Michigan the new party named “Republicans”, adopted a platform and nominated candidates for offices. In 1856 the Republicans nominated John C Fremont for President with the slogan, "Free soil, free labor, free speech, free men, Fremont." Fremont made a strong showing getting thirty-three percent of the vote, four years later Abraham Lincoln became the first Republican in the White House.
Further reading you might be interested in
The Life And Speeches Of Thomas Williams V1: Orator, Statesman And Jurist 1806-1872, A Founder Of The Whig And Republican Parties
The Republican party and its leaders;: A history of the party from its beginning to the present time