Would you mind sharing your source that shows a man named T. A. Perdue served in Company G, 31st Louisiana Infantry? I have studied the companies in this regiment that originated in Union Parish (G, H, and I) in detail, but I have not found any record of a man named T. A. Pardue/Perdue who served in Company G. There is no Louisiana Confederate Pension application for him, nor is there any record of him in the muster rolls of Company G or any other company in the 31st Regiment. I base this statement on my personal research into the microfilmed Compiled Military Service Records of the 31st Regiment, as well as a check of Booth's Index.
These Union Parish residents did serve in Company G:
Fields Heard Pardue, enlisted 6 May 1862 and served throughout the war; his wife Rebecca Jane Raney Pardue received a Louisiana Confederate Widow's Pension for his service; military record shows he was born in Butler Co AL about 1844
Milton M. Pardue, enlisted 6 May 1862 and served throughout the war; military record shows that he was born in Pike Co AL about 1842
These two Union Parish Pardues served in Company D, 4th Louisiana Cavalry Regiment:
Francis M. Pardue and T. M. Pardue (Booth's has T. M. Pardue in the 4th La Infantry, but I believe that this is a mistake and it should be "Cav.").
Are you referring to T. M. Pardue as opposed to T. A. Pardue? I cannot locate a Pardue with the initials "T. A." living in Union Parish in either 1850 or 1860.
I also cannot locate a Theodore Pardue/Perdue in Union Parish LA or Union County AR in 1860. Can you provide more details?