The american colonization society encouraged free black to move to
a. underground railroad stations
b. large northern cities
c. haiti
d. liberia

This society founded in the US in 1816 encouraged free black people to emigrate to Liberia where a new colony was set up in SW Africa. It was mainly founded by Quakers and evangelicals but also included some slaveowners in Maryland. Their migration was partly to liberate them from slavery but also to avoid a slave rebellion in the US. The Haitian black slave rebellion in 1791 may have spurred some of these slaveowners to promote this alternative,

Acase involving the laws of a single state.