Re commission dates, here's that dope for Clagett

Card #121 of his Signal Corps. CSR file:

Thomas H. Clagett, Captain, Signal Corps.

Appears on a
Register
of Appointments, Confederate States Army.
State Va
To whom report Genl. Beauregard
Date of appointment May 29, 1862
Date of confirmation Oct. 7, 1862
To take rank May 29, 1862
Date of acceptance June 1, 1862
Delivered Maj. E. P. Alexander
Secretary of War G. W. R.
Remarks: Signal Officer with rank etc. of Captain of Infantry.

Confed. Arch., Chap. 1, File No. 86, page 152