[2] He first entered service as an enlisted member of the Pulaski Light Artillery, a military battery from Little Rock.

The unit returned to Little Rock in time to fire the salute celebrating Arkansas's secession from the Union on May 6, 1861.

In the Official Records of the Union and Confederate Armies, artillery units are most often referred to by the name of their battery commander.

[9][10] Major Shoup's battalion was associated with Brigadier General Patrick Cleburne's brigade when it moved into Kentucky and remained so until after the battle of Shiloh.

The Battalion was in the retreat from Bowling Green to Corinth, Mississippi, following the fall of Forts Donelson and Henry.

Benjamin M. Prentiss's and W. H. L. Wallace's Union divisions had established and held a position nicknamed the Hornet's Nest.

The grand battery enabled Confederates to surround the position, and the Hornet's Nest fell after holding out for seven hours.

[18] All twelve-month units had to re-muster and enlist for two additional years or the duration of the war; a new election of officers was ordered; and men who were exempted from service by age or other reasons under the Conscription Act were allowed to take a discharge and go home.

Some of these officers choose to follow Major General Thomas C. Hindman, who was appointed in May 1862 to assume command of the new Department of the Trans-Mississippi.

It is not clear if Captain John Trigg chose to resign at this point or if he was defeated in the re-organization, but he drops out of sight in the Army of Mississippi at about the time of the reorganization.

Trigg's Arkansas Battery is listed in General P.G.T Beauregard's report of the Confederate Army of the Mississippi on May 26, 1862.

Unlike other senior Arkansas leaders of the Army of Mississippi who returned to Arkansas in the summer of 1862 helping General Hindman organize a new Army, Trigg is not mentioned again in military service until a September 1863 order that directs him and his company to joint General Sterling Price's Division.

General Hindman arrived back in Little Rock in late May 1862 and found that Governor Rector had fled with the state government to Hot Springs.

Hindman would implement martial law in Arkansas, which resulted in complaints from Governor Rector to Confederate President Jefferson Davis.

Trigg, who was a half brother to and former law partner of Governor Rector would have ample reason to lie low until Hindman was transferred back east of the Mississippi River in Spring of 1863.

(Tuscaloosa, AL: Fire Ant Books, 2005)., lists Trigg's Battery as the Clark County Light Artillery.