Are we sure these are not just occupational license tags? I don't think we can be certain on how these tags were looked upon during the stated time period. I don't think the term, "Slave hire tags" may be 100 percent correct. Freemen may have also been required to use them. Slave s were a merchandise with papers just as land,, etc. during that time period. Not trying to stur the pot, just looking at facts I have studied. Remember the history of yesterday is oft changed to fit the politics of today. They are wonderful items of history, no matter how you look at them.
DG