The 14th Texas Dismounted Cavalry served in the Army of Tennessee and was not at the Jenkin's Ferry Battle.
On April 5, 1864, at Lauderdale Springs, Mississippi, there were twenty officers and 206 enlisted men present in the regiment.
The unit participated in the battle of Jenkins' Ferry on April 30, where one company lost nearly half the men, and as a result many sergeants and captains were promoted.
Shortly thereafter, the brigade, now in Maj. Gen. Samuel G. French's Division of Polk's Corps, was sent to northern Georgia.
The second line above is the mistake, as it would have the regiment in Mississippi on April 5, then racing across the Mississippi River [which would have been quite an accomplishment at that time], then fighting at Jenkin's Ferry, and racing back across the river to fight in the Atlanta campaign.
Looks like it might have been a cut and paste entry from another regiment.