When was slavery introduced?

Slavery in the US had been practiced for roughly a century before the Revolutionary War.

ANSWER:

The first evidence of slavery in the American Colonies, comes from sales records of the 1640's. The slaves were in the Chesapeake colonies.

The first legal recognition of slavery was a Virginia statute in 1662, which said that the status of a newborn child depended on the status of the mother. If she was free, the child was free; if she was a slave, the child was a slave. This made slavery inheritable.