An Act of the US Congress concerning slavery. Following the Mexican–American War, the Compromise of 1850 had allowed squatters in New Mexico and Utah to decide by referendum whether they would enter the Union as “free” or “slave” states. This was contrary to the earlier Missouri Compromise. The Act of 1854 declared that in Kansas and Nebraska a decision on slavery would also be allowed, by holding a referendum. Tensions erupted between pro-and anti-slavery groups, which in Kansas led to violence (1855–57). Those who deplored the Act formed a new political organization, the Republican Party, pledged to oppose slavery in the Territories. Kansas was to be admitted as a free state in 1861, and Nebraska in 1867.
Subjects: warfare and defence — United States history.