The term exoduster generally refers to the thousands of African Americans that left the South for Kansas after the end of Reconstruction in 1877, rather than live under repressive white supremacist state governments. Yet theirs was not the first noteworthy black exodus into the state. Having entered the Union as a free state in January 1861 after years of bloody conflict between pro-slavery and anti-slavery forces, Kansas became a natural refuge for Missouri slaves early in the Civil War. With the collapse of order in Missouri during the late summer and early fall of 1861, a number of the state’s slaves had a chance to escape to freedom in Kansas. This phenomenon was noted in the November 8, 1861 issue of the New York Times, reprinting an October 3o article from the Leavenworth Conservative. It read in part:
The flight of Missouri slaves to Kansas proves yet again a great truth of emancipation in the Civil War. When the opportunity arose for slaves to free themselves by fleeing many did so. Certainly favorable circumstances needed to arise such as the arrival of the Union army in the vicinity, or in the case of Missouri slaves, civil disorder and free territory emerging nearby. So while the slaves did not free themselves, they often were active players in achieving their freedom, and one common action they took in that regard was flight. Fortunate slaves, such as those at Port Royal, South Carolina, in November 1861 effectively had freedom handed to them by the Union army when it arrived. Other slaves took a more active role in their own liberation by fleeing, often at considerable risk, to where they might be free. Such was the case with hundreds of Missouri slaves in Fall 1861.
Source: http://www.nytimes.com/1861/11/08/news/southern-kansas-movements-of-gen-lane.html