What might the family names signify?

If you pay close attention to the names in the story, you will see a pattern. For example, of the Sweet Home Men, three share the same first names: Paul D, Paul F, and Paul A. Notably, all share the same last name as well (except for Halle). These names are significant because they illustrate how black men (slaves) were not afforded personal identities and were all considered the same (property). The only individual factor that was considered was how much money they could garner if sold. 

The fact that Baby Suggs took her own name would have been a rarity (she had no name). She refuses the name Halle tries to give her (Jenny) and asserts her first act of freedom in choosing her own. 

Denver's name was chosen to honor the woman who assisted her mother when she gave birth. It was a name given in respect for another person's actions.