Yes you are correct MC.I remember now we had this discussion years ago on the Dallas History Message Board.I just pulled up the picture of his tombstone..

John Neely Bryan
Pvt
18th.Tx.Cav.CSA
Dec.24,1810-Sep.8,1877
Founder of Dallas Texas

Maybe all those years dealing with the Dynamic Sarah Cockrell made him loopy....

I also note that a D.B.Thomas on the 1860 census in Dallas is a physician.Its possible the surgeon D.B. Thomas of the 6th Texas Cavalry and that D.B.Thomas serving early in Good's Battery may be one and the same.

MWT