Keep in mind that after the emancipation of the slaves they were free to choose any names they wanted. The former slave could keep the name given to him by his master, or give himself any name of his choosing.

During slavery the slaves had only first names. Any published records, such as wills or deeds referred to them by first names only.

After the end of slavery a former slave who used to be called Jacob may have changed his name to Edmund Brown.

Don't get caught up in the myth that almost all former slaves chose the surname of the men who once owned them. In many many cases that just wasn't the way it was.