In September 1862, Confederate forces invaded the North. They headed for Maryland where they thought Southern sympathizers would rise up and join them. Instead, they encountered Union troops at South Mountain, between Frederick and Hagerstown, on September 14, 1862. During the fierce battle, a brigade of Midwestern regiments caught the attention of Union General George McClellan. Colonel John B. Callis of the 7th Wisconsin Infantry tells how McClellan unwittingly gave them the name "Iron Brigade".
The late General John B. Callis, formerly of the 7th Wis., in a letter said, General McClellan told me at the Continental Hotel in Philadelphia what he knew of the origin of the name "Iron Brigade"
[McClellan told Callis that] "It was during the battle of South Mountain, my headquarters were where I could see every move of the troops on the pike. With my glass, I saw the men fighting against great odds. When General Hooker came, in great haste, for orders, I asked him what men those were fighting on the pike. He said: 'General Gibbon's Brigade of the Western men.' I said: 'They must be made of iron.' He said: 'By the Eternal, they are iron!' I replied: 'Why, General Hooker, they fight equal to the best troops in the world.'
"After the battle I saw Hooker at the Mountain House, near where the brigade fought. He sang out, 'General, what do you think of my Iron Brigade?' Immediately from and after the battle, the brigade took upon themselves, of course, having heard of this incident, that name; no brigade seemingly denying them the right to do so, and, in fact, the entire Army of the Potomac conceding to them that right."
Source: "Newspaper Clippings, 1861-1930", Vol. 7, page 20 (from the National Tribune, September 22, 1904)
View the full document