as the u.s. moved toward civil war the republican party grew out of
History of the United States Republican Party The Republican Party began as a coalition of anti-slavery Conscience Whigs and Free Soil Democrats opposed to the Kansas–Nebraska Act, submitted to Congress by Stephen Douglas in January 1854. The Act opened Kansas Territory and Nebraska Territory to slavery and future admission as slave states, thus implicitly repealing the prohibition on slavery in territory north of 36° 30′ latitude, which had been part of the Missouri Compromise. This change was viewed by Free Soil and abolitionist Northerners as an aggressive, expansionist maneuver by the slave-owning South.
American Civil War The American Civil War (also known by other names) was fought in the United States from 1861 to 1865. As a result of the long-standing controversy over slavery, war broke out in April 1861, when Confederate forces attacked Fort Sumter in South Carolina, shortly after U.S. President Abraham Lincoln was inaugurated. The nationalists of the Union proclaimed loyalty to the U.S. Constitution. They faced secessionists of the Confederate States, who advocated for states' rights to expand slavery.