When free people bought their own wives and children out of bondage, the purchase was legally ownership but in practice a rescue. Neighbours may have known the people bought as family members, not as property. The same legal act could carry opposite meanings.
Freedom could be granted on paper and still be made fragile by law. In Virginia, freed slaves had a year to leave the state or they would be put back into slavery. Release did not end a person's dependence on the system's rules.
People who were once held as property can, once they gain money and freedom, buy and keep people of their own. This happened because the system made owning people the visible mark of success, not because race decided who owned whom. Lines of race and power become tangled and hard to draw.
A person promoted from among the oppressed to oversee them can end up working them harder than anyone, even his own wife. He holds on to the small authority he has been given, and those under him still go back to their cabins hungry and tired.
An institution like slavery does not only harm those it holds down; it reshapes everyone who lives within it, owners and owned alike. Some people manage to rise above it and others give way. A man who once insisted that his wife and he were one family can, years later, come to see that same family as an obstacle to his own advancement.