The Compromise of 1850 sought to settle the question of whether newly acquired territory from Mexico would allow slavery. The Utah and New Mexico territories would allow slavery and would later be able to vote on the slavery issue themselves.

The new version of the Fugitive Slave Law required federal judicial officials in all states and federal territories, including in those states and territories in which slavery was prohibited, to assist with the return of escaped slaves to their masters actively in the states and territories permitting slavery.

In 1854, during the organization of Kansas and Nebraska Territories, Senator Stephen Douglas of Illinois spearheaded the Kansas-Nebraska Act, which mandated that the settlers of each territory should decide the issue of slavery for themselves, a principle known as popular sovereignty.

The Congress of the United States abolished slavery in all federal territories in 1862 (Act of June 19, 1862).

West Central Africa

That day—January 1, 1863—President Lincoln formally issued the Emancipation Proclamation, calling on the Union army to liberate all enslaved people in states still in rebellion as “an act of justice, warranted by the Constitution, upon military necessity.” These three million enslaved people were declared to be “then.

What led to the outbreak of the bloodiest conflict in the history of North America? A common explanation is that the Civil War was fought over the moral issue of slavery. In fact, it was the economics of slavery and political control of that system that was central to the conflict.