The Journey of Little Charlie by Christopher Paul Curtis

Newbery Medalist Christopher Paul Curtis brings his trademark humor and heart to the story of a boy struggling to do right in the face of history's cruelest evils.
Twelve-year-old Charlie is down on his luck: His dad just died, the share crops are dry, and Cap'n Buck-the most fearsome man in Possum Moan, South Carolina-has come to collect a debt. Fearing for his life, Charlie strikes a deal with Cap'n Buck and agrees to track down some thieves. It's not too bad of a bargain for Charlie...until he comes face-to-face with the fugitives and discovers that they escaped slavery years ago and have been living free in Detroit. Torn between his guilty conscience and his survival instinct, Charlie needs to figure out his next move-and soon. It's only a matter of time before Cap'n Buck catches on...