On the second day of the battle, the extra time gained by the troops rallied by Carson's actions allowed most of the Union Army to retreat to the defenses of Chattanooga, Tennessee, without pursuit by the Confederate soldiers.

This delay allowed most of the Union Army on the field, including most of the XIV Corps to which the regulars were assigned, to retreat to a more secure position at Chattanooga.

[2] On September 2, 1861, Carson enlisted in the 15th United States Infantry Regiment, and was assigned to Company "E", 1st Battalion, under the command of Captain Henry Keteltas.

His distinguished record earned him a high amount of praise from officers and fellow soldiers and eventually the Medal of Honor for his gallantry at the Battle of Chickamauga.

[17] On the first day of the Battle of Stones River near Murfreesboro, December 31, 1862, Rosecrans and Bragg both intended to attack their opponent's right wing.

[20] Rousseau's forces formed to the right of Brigadier General Philip H. Sheridan's division which was holding the right side of the line while men of the units in retreat passed by.

[23] The strong Confederate attack finally forced the regulars to withdraw from the woods toward the rear of their original position near a railroad line and the Nashville pike.

[30] Finally, and only after their officers themselves recognized the danger, the Regular Brigade had to retreat across the open cotton field to the railroad line and the cover of their batteries on another nearby knoll as the Confederates again advanced in large numbers.

[32] The battle wound down and was broken off due to the cold, rainy weather and the exhaustion of the men but the two armies stayed in position on the battlefield.

He also demonstrated his courage in performing his job under precarious conditions and in rescuing one of his wounded comrades under fire and protecting him from death or capture.

[45] As the campaign started, Major Sidney Coolidge had to take command of the Regular Brigade because Brigadier General King's previous wound had not healed sufficiently to permit him to serve in the field.

[48][49][50] After participating in the Tullahoma campaign's maneuvers, the Regular Brigade had spent its time drilling and then repairing roads and guarding railroad lines.

[53] Captain Albert B. Dod had joined the 15th U.S. Infantry and, since he outranked Captain Keteltas, assumed command of the 1st Battalion while Keteltas resumed command of Company E.[52] After marching his army into Chattanooga, Major General Rosecrans continued to advance his force through southeastern Tennessee and into northern Georgia but his troops were widely dispersed.

[66] At this dire and critical point in the battle when the XIV Corps lines were wavering and in disorder, on his own initiative, Bugler William J. Carson of Company E, the 1st Battalion, 15th U.S. Infantry, with his bugle in one hand and a sword in the other, blew repeated calls, including "halt," "rally," and "forward" calls, in a successful attempt to rally the remaining Union troops.

[71] The worn out Union troops held their position at nightfall on September 19,[72] Unlike his actions at Stones River, Bragg planned to renew the attack because he had 11 brigades on hand or about to arrive which had not participated in the battle on the first day.

[74] Meanwhile, Brigadier General King placed his men in a column of battalions in an effort to ward off a flanking attack by the Confederates if the regulars had to defend the end of the line.

[77] The Confederates in fact soon attacked the Union left but they did so in a piecemeal and disorganized manner that allowed the regulars to defend their position with few initial casualties.

[79] The advancing Confederates turned down the La Fayette Road to deliver a flanking attack, which scattered Dodge's men after they had fired only one volley.

[79] Historian Mark W. Johnson says it was at this point that the 18th received "a one-man reinforcement," Private William J. Carson, bugler of the 1st Battalion, Company E, 15th U.S.

Still sounding the rally, I passed back and forth of the forming line, and what a few minutes before seemed a hopeless disastrous rout, now turned out to be a complete victory.

[81] With the arrival of some timely reinforcements, the Union left wing was strong enough to throw back the Confederate attack, although the battle continued.

[87] Heavy casualties were sustained by both sides in the battle, with the Regular Brigade suffering 56 per cent of its men killed, wounded or missing.

[90] Carson and many other soldiers of the Regular Brigade and a few other supporting regiments did not escape with most of Thomas's men but were captured late in the day after they ran out of ammunition.

[81][91] Nonetheless, Carson's bugle calls earlier in the day had not only rallied the troops but had led the Confederates to believe that the Union line had been reinforced.

[91] By the time the charge was made and the small group of remaining defenders had to surrender, most of the Union Army that had not fled even earlier in the day had escaped and was nearing the defenses of Chattanooga.

W. J. Carson, along with 1900 of us, after being completely surrounded by the enemy, and out of all ammunition, were captured at 6:30 P. M. on the original line of battle, the entire army, at that time, having retired several miles toward Chattanooga.

COLONEL: At the request of Major-General Rosecrans, I have the honor to make the following report of Private William J. Carson, bugler in the First Battalion, Fifteenth U. S. Infantry; On Saturday, September 19, when the regular brigade was falling back, he behaved with most conspicuous gallantry; with a sword in one hand and his bugle in the other, he sounded constantly the "Halt," the "Rally," and the "Forward;" espying a stand of colors belonging to the Eighteenth U. S. Infantry, he rushed up to them and sounded "To the color."

On Sunday, September 20, before our battalion was engaged, the Eighteenth, being pressed by vastly superior numbers, was falling back; Carson by some means became the possessor of a musket and constituted himself a "provost guard."

Private Carson's official Medal of Honor citation reads: The President of the United States of America, in the name of Congress, takes pleasure in presenting the Medal of Honor to Musician William J. Carson, United States Army, for extraordinary heroism on 19 September 1863, while serving with Company E, 15th U.S. Infantry, in action at Chickamauga, Georgia.

At a critical stage in the battle when the 14th Corps lines were wavering and in disorder, Musician Carson, on his own initiative bugled "to the colors" amid the 18th U.S. Infantry who formed by him, and held the enemy.