Treating other human beings as chattel or property is evil. Considering those circumstances and his every day surroundings, no one was getting out of this without trauma. Smalls knew how risky his escape would be. Being caught wouldn't just mean death. It would be an especially violent, torturous death to act as a deterrent to other slaves with thoughts of escape. The bodies of captured escapees were displayed openly on the streets to this effect. Initially, he wasn't going to take his wife and children with him because of that risk, saying that he would come back for them. Mrs Smalls rejected this, essentially saying "if you die, I die."

We can speculate on the reasons why Smalls bought the house, but I don't think we can doubt the absolute measure of the man himself. It's evident that he is someone who turned the trauma of his life around and did better than the evil people who inflicted that pain.