I think this would be Peter Byrne of Cape County. He has 12 slaves in the 1860 census, one of which is 21 y/o Zeno Byrne found on the
Cape USCT enlist list. Byrne's relative (Cousin?) Luke (aid to M Jeff Thompson?) is in New Madrid and has several slaves in both the 1850 and 1860 census. He also lost slaves to the USCT.

John R