I suggest reading Two Princes of Calabar by Randy Sparks. An interesting historical account of two African princes from slave trading towns who were enslaved and travelled from the Americans to Europe and back to Africa. Their letters are some of few written first hand accounts of the trans Atlantic slave trade from the perspective of enslaved people's. They had a lot of connections in Africa with Europeans and African slave traders due to their family ties and used them to make there way out of slavery. Can't remember what happens to them in the end but it's a good read.
I'm sure there are more examples, but this question was asked before and got some good answers from u/sunagainstgold, u/bg478 and u/swarthmoreburke.