George:

I don't find him in MS CS Graves Registrations.

I don't find him in the 7th MS in MS CS Pension Applications, but I do find him in the 26th MS therein.

Isaiah Barnett, 26th MS, 1906, Lee County.

Lula Barnett, 1918, Lee County; said her husband Isaiah Barnett was in the 26th MS Infantry.

In Howell, I don't find him in the 7th MS.

However, in Howell, I do find Isaiah Barnett, Pvt., Co. I (Capt. Burton's Co., raised in Itawamba, Pontotoc, and Tishomingo Counties, MS), 26th MS Infantry.

I also find Isaiah Barnett as a member of the Boomerangs, i.e., Capt. Taylor's Co., a local defense company (but county of origin not specified).

Hope this helps! -- Jim Huffman, Gainesville Vols