There appears to have been only one engagement at or near Camp Eagle Pass.

EAGLE PASS, TEXAS
20-21 June 1864
CONFEDERATE FORCES
Post of Eagle Pass
CAPTAIN JAMES A. WARE
34 Garrison Troops - Captain James A. Ware
Stone's Homeguard Company - Lieutenant Burke
Detachment, Pickrell's Company
Hudson's Company
CASUALTIES - Not Reported

Additional info from other sources (each number is from a different source):

1. The 1st Texas Cavalry Regiment, aka 1st Texas Mounted Rifles was organized by the merging of the 3rd and 8th Texas Cavalry Battalions in May of 1863. On June 19, 1864, one company of the regiment engaged the enemy at Eagle Pass.

2. During Civil War, the post was occupied by Confederate troops of "Frontier Regiment".

3. Per “The Handbook of Texas Online”: During the Civil War, a party of renegades [Unionists, including regular Federal troops] crossed from Piedras Negras and overran the Confederate garrison at Fort Duncan. The townsmen, fighting from behind a barricade of cotton bales, successfully drove off their assailants.

4. This is the only other unit that I have found to have been in that area during the war: Per Jim Martin, at least a part of Wood’s 32nd/36th Texas Cavalry patrolled the Eagle Pass area from approximately July 1862 to August 1863.

I think that I have a little info on Todd as a gunmaker. I'll take a look and post if I find anything.