Confederates win the civil war and their independence from the North. In the follow up they completely shut down the borders with the US and guard them with troops and barbed wire. Several African slaves escape around 1870 after and, while the South is expecting them to flee to the US, they head to Liberia. Liberia refuses to surrender the ex-slaves and soon becomes a haven for escaping slaves who do not want to join the still-racist north.
In 1877 the Confederacy finally decides they've had enough and declare war on Liberia. As it becomes clear the tiny African state can do nothing to stop the invasion but still refuses to give up the slaves, massive numbers of black citizens flee the country fearing they are going to be enslaved. After the war ends Liberia is declared a Confederate colony and the local blacks who have no escaped are enslaved.
As time goes on the coast of Liberia develops as a major trading port for European-African colonies wishing to sell goods to the America's and as a result more and more white's move in. By the turn of the century the colony is large majority white.
Also by the turn of the century many nations have placed embargoes on the Confederacy, demanding their slavery practices be ended. When the Confederacy refuses to do so the white citizens of Liberia, whose entire economy is port and trade based, fear economic collapse. As a result they declare independence and outlaw slavery in 1904 with US backing. There
