This is the only 1862 reference I could find in the OR re Nelson's Brigade

HDQRS. TRANS-MISSISSIPPI DEPARTMENT,
Little Rock, Ark., September 28, 1862.

SECOND DIVISION, Brig. Gen. A. NELSON commanding.

First Brigade, Brigadier-General Nelson commanding.--First, Nelson's [10th] regiment Texas Infantry; second, Sweet's regiment Texas Infantry; third, Darnell's regiment Texas Infantry; fourth, Taylor's regiment Texas Infantry; fifth, Gould's battalion Texas Infantry.

Second Brigade, Col. George Flournoy commanding.--First, Flournoy's regiment Texas Infantry; second, Waterhouse's regiment Texas Infantry; third, Allen's regiment Texas Infantry; fourth, Fitzhugh's regiment Texas Infantry.