How did the trade with africa most the american colonies

By Slave trade.

Explanation:

American colonies helped by Africa through "Triangular trade", Triangular trade is done between three countries over the Atlantic sea route. The Triangular route covered England, Europe, America, Africa, and west indies. this trade is common practice during the 16th to early 19th century, west indies and Africa provide slaves to the American colonies.Merchants exchanged goods with African slaves then they shipped these slaves to America and buy raw goods there with the exchange of African slaves and sell those raw goods back in Europe. In a short period Merchants who do this trade become so rich because the American raw good is in high demand in the European market plus American colonies also getting high profit due to this trade.American colonists using African slaves in agricultural and other industrial work and earning high profits.