Coram Boy by Jamila Gavin

Coram Boy is the epic story of a man who trades in illegitimate children and a child who is reunited with his father.
It is the tale of two cities: Gloucester and London.
It is the tale of two boys: Toby, saved from an African slave ship, and Aaron, the illegitimate son of the heir to a great estate.
It is the tale of fathers and sons: Otis, dealing in the vilest trade of all, and his son Mashek, not quite of this world; Sir William Ashbrook, landowner, and Alexander, the son he disinherits.
An epic journey fraught with every danger and excitement, until love triumphs over hatred and corruption.