Co. K, 7th Wisconsin Infantry
What we know today as the "Iron Brigade" had it's beginnings in the Fall of 1861 when the 2nd, 6th, and 7th Wisconsin Infantry Regiment's and the 19th Infantry Regiment were joined together in a brigade under the command of Brigadier General Rufus King. Of these regiments, only the 2nd Wisconsin had been in any kind of combat being present at the First Battle of Bull Run (Manassas) on July 21, 1861. The brigade would also include Battery B, 4th United States Artillery and it would assigned to the defenses of Washington, D. C. for the next nine months or so. While staying manning Washington's defenses, the brigade would become recognizable almost immediately for two reasons, one it was the only all-western brigade in the Eastern Theater and two because of the Model 1858 Hardee Hat that was issued to the brigade. This hat itself earned the brigade it's "Black Hats" nickname. The brigade would not go with the Army of the Potomac when George McClellan attempted to march on Richmond, Virginia by going up the Virginia Peninsula, so the brigade avoided the bloody Seven Days' battle. Instead they would march to Fredericksburg, Virginia to take up a reserve position with the Major General Irwin Mcdowell's Infantry Corps.
By August 1862, Brigadier General John Gibbon was in command and the brigade was attached to General John Pope's Army of Virginia in an attempt to hunt out and destroy "Stonewall" Jackson's Confederates operating somewhere in northern Virginia. Jackson would find Pope instead. On August 28, 1862, General Jackson came out of hiding and attacked Gibbon's brigade at Brawner's Farm near the old Bull Run battlefield. The fight that ensued was nothing short of an all out slug fest. Jackson committed the better part of four brigades in an attempt to drive off Gibbon's men but they slugged it out round for round with the Jackson's veterans. The discipline that had been pushed upon the men by General Gibbon paid off in the fight. All told in three hours of savage fighting where the opposing lines were less than 30 yards apart, the men of Gibbon's brigade lost nearly 800 men out of over 2,000 engaged while inflicting over 1,000 casualties on the attacking Confederates. The brigades trial by fire showed that the western men would fight. They would go on to fight in the Union disaster that was Second Bull Run and retreat back to the defenses of Washington. The brigade remained in Washington where it was transferred to the Army of the Potomac and into the First Corps under the command of Joseph Hooker.
Between September 4-7, 1862, General Robert E. Lee marched his seemingly invincible Army of Northern Virginia north across the Potomac and into Frederick, Maryland where they would eventually march west in the hopes of pushing the campaign into Pennsylvania. Gibbon's men and the First Corps were ordered to march out of Washington on September 5th marching toward Brookville and eventually towards Frederick. The advance elements of the Union Army arrived in Frederick on September 12th and by the 13th, McClellan had most of his army massed in and around Frederick. As the Union Army encamped at Frederick on the 13th, a piece of paper outlining Robert E. Lee's plans for his campaign which called for the division of his army and the capture of Harpers Ferry, Virginia. General McClellan used this document to put his army in motion. On the 13th, the lead elements of the Union Army pushed through the passes within the Catoctin Mountain range and advanced right up to the base of South Mountain.