Charleston is a colony seaport town and thus a slave trade port. Crow's Nest is a tavern.
Some of the newly purchased slaves come from prior bondage in other slaving communities (a few from Africa direclty). Slave auctions are often held there, and men came from other places (even as far as Kentucky) to participate.
On the whole, most of the slave population was a mature one, with second, even third generation slaves. The slaves are Christians and encouraged to form their own services.