Answer :

An enslaved person who learned a skilled trade most likely worked for a saddle maker.

The Agriculture industry was the main economic activity in the Southern States of the United States during the 19th century. Businessmen and landowners from these territories relied on slaves as the main source of labor. The vast majority of them ended up working on cotton fields. However, if a salve was skilled enough, he could exercise more specialized work, such as the manufacturing of saddles for horses, which were the main form of transportation during that period.