Can anyone help me out by identifying the given names of the following officers?

Maj. J. B. Gordon (6 Ark Inf)
Lt.Col. W. Y. McCammon (9 Ark Inf)
Lt.Col. S. S. Ford (10 Ark Inf)
Lt.Col. W. D. S. Cook (12 Ark Inf)
Lt.Col. A. R. Brown (13 Ark Inf)
Lt.Col. A. D. Grayson (13 Ark Inf)
Maj. J. H. Messick (14 (Mitchell's) Ark Inf)
Lt.Col. P. R. Smith (19 (Dawson's) Ark Inf) - possibly Pascal?
Lt.Col. W. R. Kelley (20 Ark Inf)
Lt.Col. H. G. Robertson (20 Ark Inf)
Lt.Col. B. S. Johnson (27 Ark Inf)
Maj. R. R. Henry (38 Ark Inf)
Lt.Col. G. R. Jones (45 Ark Inf)
Maj. C. J. Washburn (45 Ark Inf)
Lt.Col. S. J. McGuffin (46 Ark Inf)
Maj. E. N. Floyd (46 Ark Inf)
Maj. W. S. Hanna (47 Ark Inf)
Col. Fitzwilliams (Adams' Regiment)
Lt.Col. Hill (Adams' Regiment)
Maj. W. D. Trotter (Hardy's Regiment)

Many thanks in advance...

Phil Osborne