The regiment fought at Eltham's Landing, Seven Pines, Gaines's Mill, Second Bull Run, South Mountain, Antietam, and Fredericksburg in 1862.

Soldiers were recruited from Colorado, Harris, Jefferson, Leon, Liberty, Milam, Montgomery, Polk, Trinity, Walker, and Washington County, Texas.

[1] On 7 May 1862, Confederate army commander Joseph E. Johnston ordered John Bell Hood and his Texas brigade to "feel the enemy and gently fall back".

The Battle of Eltham's Landing occurred when the Texas brigade bumped into William B. Franklin's Federal troops.

With other units of William H.C. Whiting's division in support, Hood's Texans drove their foes back more than a mile.

[3] The Texas Brigade arrived late on the field during the Battle of Gaines's Mill, but played an important part.

[6] The next day at 4:00 pm, James Longstreet and Lee launched a major assault at the Union left flank; it was led by the Texas Brigade.

[13] The Battle of Antietam was fought on 17 September, but on the previous evening Hood's division clashed with Federal troops before being pulled back into reserve.

[14] At 7:00 am next morning, after the initial Union attack broke through the Confederate first line, the 2,300 men of Hood's division were thrown into the battle.

[18] Shortly after the attack started, a bursting shell seriously wounded Hood, leaving his division without his guiding hand.

[20] Private William A. Fletcher of the 5th Texas admitted that, after the first attack, he and other troops bolted as soon as they entered the zone of heavy fire where his comrades lay dead or wounded.

But before the Texas and Alabama soldiers could exploit the gap, General Warren plugged it with the 140th New York Regiment and the Confederates were forced to retreat.

One soldier of the 5th Texas recalled bitterly that Little Round Top would have been impregnable even if the Federals had been armed with rocks.

Robertson's brigade drove the opposing Union troops back to the Viniard House on the Lafayette Road.

When they tried to advance farther they were stopped by John T. Wilder's Union brigade armed with Spencer repeating rifles.

[23] On the second day, the Texas Brigade was part of the assault column that drove through a gap and routed the Union right wing.

While the 4th Texas scattered to the rear, another Confederate brigade mistakenly started firing at Robertson's men from a different direction.

Harker's Union troops then moved forward and fired on the 5th Texas, which had fallen behind and was dashing to catch up with the brigade.

The brigade was part of Charles W. Field's division in Longstreet's Corps and Lieutenant Colonel King Bryan commanded the 5th Texas.

General Lee attempted to lead the counterattack, but the men of the Texas Brigade shouted, "We won't go on unless you go back".