Crispus Attucks
Attucks himself may have been a freeman, or may have escaped slavery.  However, some evidence suggests that Attucks was born a slave in Framingham, Massachusetts, but escaped from slavery.  In 1750, William Brown, a slave-owner in Framingham, put out an advertisement about a runaway slave named Crispus. In the advertisement, Brown offered a reward of 10 pounds to whoever found and returned Attucks to him. The description in the advertisement fit Crispus Attucks.  This suggests that Attucks was a runaway slave.  Still, people have argued for decades about whether Attucks was a free black man or a runaway slave.