Memory Game Causes for the Civil WarOnline version Identify the causes that led to the American Civil War. by Andrew Balzer Compromise of 1850 Sectionalism It required that all escaped slaves, upon capture, be returned to their masters and that officials and citizens of free states had to cooperate. Kansas-Nebraska Act Fugitive Slave Law Uncle Tom's Cabin Let the people of the territories themselves decide whether slavery would be permitted. It allowed people in the territories of Kansas and Nebraska to decide for themselves whether or not to allow slavery within their borders. Popular Sovereignty California entered as a free state loyalty to one's own region or section of the country, rather than to the country as a whole Novel written by Harriet Beecher Stowe that showed the horrors of slavery.