By the 18th century, 45,000 Africans are transported annually on British ships. 1700s: Almost half of the slaves coming to North America arrive in Charleston. Many stay in South Carolina to work ...

1750: 61% of all British North American slaves -- nearly 145,000 -- live in Virginia and Maryland, working the tobacco fields. 1770: Crispus Attucks is killed in the Boston Massacre. 1775 ...

By the 1860s, Britain was growing tired of maintaining its colonies. The costs, especially of defending British North America, were burdens that a growing number of British politicians could do ...