301C: A boy is dropped off at a “poor house”

The book that I am looking for is as follows:

Set in the time of US slavery, this children’s story opens with a very young boy being anonymously dropped off a horse drawn wagon at a the end of the driveway of a rural ‘poor house’ in a northern US state. It turns out that his slave mother was forced to leave him behind while fleeing her ‘owner’ and the father of her baby as she tried to reach Canada via the underground railroad.

The reader does not have this information at the start of the tale but rather learns this as the story unfolds. The story follows the little boy who is taken in by the operators of the ‘poor house’, however unwillingly. In return for lodging he is assigned chores and when old enough goes to school and makes friends. His closest friend, however, is one of the other residents, a giant male adult with mental health issues that cause him to occasionally become violent, which necessitate that he be kept in a cage in the house so that he will not harm others. Near the end of the story, this man (perhaps severely afflicted with severe SAD) is killed in an accident in a rock quarry where he works when mentally able to do so.

The little boy is visited by a white man from the south, and eventually comes to understand that this man is not someone with good intentions, in fact he is his father. He has been pursuing both he and his mother who had managed to escape. I forget all the details of the story, however, the boy does end up safely in Canada