I discovered this extremely interesting book on Project Gutenberg: The Interesting Narrative of the Life of Olaudah Equiano, Or Gustavus Vassa.
Olaudah Equiano was kidnapped from his village in Africa when he was about 11 years old. His name was changed three times, finally to Gustavus Vassa, the name he went by for most of his life. His experience was very different from that of most African slaves. He had several owners, most of whom were kind masters and he was taught to read and write, however, though he was comparatively well-treated he did suffer many of the indignities and hardships that were common for black men at the time.
Vassa spent much of his life at sea. He served as a steward to an officer in the British Navy for a number of years then was sold to a Quaker merchant whom he served as a clerk, mostly in the Caribbean islands. He was allowed to earn money by buying and selling items such as glassware and fruit which enabled him to buy his freedom. As a free man he continued to work on ships off and on as well as having a few jobs on land, mostly in Britain.