Answer:
Step-by-step explanation:
Slavery in what would become the United States was established during European colonization. In 1776, slavery was legal throughout the Thirteen Colonies, after which colonies started to abolish the practice. Pennsylvania abolished slavery in 1780, and about half the states abolished slavery by the end of the Revolutionary War or in the first decades of the new country, although this did not always mean that existing slaves were freed. Although not one of the Thirteen Colonies, Vermont declared its independence from Britain in 1777 and at the same time limited slavery, before being admitted as a state in 1791.