The 19th Indiana organized at Indianapolis and mustered in July 29, 1861. Which then left for Washington DC on August 5th. Attached to the 3rd Brigade, McDowell’s Division, Army of the Potomac till April 1862 which it then became part of King’s Division (under the command of General Rufus King of Wisconsin), Dept. of the Rappahannock, which was composed of the 2nd, 6th, and 7th Wisconsin till June of 1862. At this time this brigade then became part of the 4th Brigade, 1st Division, 1st Army Corps, Army of the Potomac, under the leadership of General John Gibbon (a West Point Grad) that came east with Battery B, 4th US Artillery. It was at Brawner Farm in Gainsville, Virginia on August 28, 1862 where the brigade saw its first significant action. Running into Stonewall’s Division, the brigade stood their ground, showing the Confederates that they were up against an entirely different kind of Union Brigade (one that didn’t break and run).
This group of regiments were originally called “The Black Hat Brigade” because the soldiers wore the regular army dress hat (the Hardee Hat) instead of the more typical blue cap (called a Bummer Cap). This Brigade was the only all Western Brigade in the Army of the Potomac.
The nickname “Iron Brigade” was received at South Mountain on September 14, 1862 when General McClellan had told General Hooker that General Gibbon’s Brigade of Western men seemed to be made of iron and Hooker’s reply was that if had seen them fight at Second Bull Run that they are made of iron and after the battle at South Mountain Hooker asked what McClellan had thought of the Iron Brigade and since that time McClellan referred to them as the Iron Brigade. After the battle of Antietam in Maryland the brigade was reinforced by the 24th Michigan Volunteers, because of heavy losses the brigade sustained in the battle. Battery B of the 4th US Artillery, comprised in large part infantry detached from the brigade, was closely associated with the unit.
It was at the battle of Gettysburg on July 1, 1863 that the Iron Brigade almost ceased to exist. The Brigade lost a total of 1,153 men engaged. When the war was over the records showed that the brigade lead all other Federal Brigades in percentage of battle deaths.
The 19th Indiana Regiment had the highest percentage of killed in battle from the state of Indiana. The regiment lost during service 5 Officers and 194 Enlisted men killed and mortally wounded and 1 Officer and 116 Enlisted men by disease for a total loss of 316. The total number of wounded was 396 for a combined total of dead and wounded of 712. In it’s very first battle at [Second] Manassas it lost 259 out of 423 engaged, or 61 percent.