And three of the Wisconsin Volunteer Infantry Regiments became part of what would become the excellent Iron Brigade. In their first engagement at Brawner's Farm they defeated the already famous Stonewall Brigade.
The rookies of the brigade gave up not one foot of ground in a stand-up fight that cost them heavily. The only troops that gave any ground at all were those who were shot and fell backwards, falling back a foot or two as they fell wounded or dead.
See Mr Lincoln's Army by Bruce Catton.
Keith Rocco has done an excellent artillery print of the brigade's attached artillery battery at Antietam.
Other sources for the Iron Brigade are:
-The Iron Brigade by Alan Nolan.
-The Sixth Wisconsin Volunteers by Rufus Dawes.
-History of 24th Michigan of the Iron Brigade by OB Curtis.
-Giants in Their Tall Black Hats: Essays on the Iron Brigade, edited by Alan Nolan and Sharon Vipond.
-Those Damned Black Hats: The Iron Brigade in the Gettysburg Campaign by Lance Herdegen.
-Personal Recollections of the Civil War by John Gibbon.
John Gibbon, who was an artillery officer, wrote The Artillerist's Manual, an excellent volume on the artillery of the period.
Wisconsin was one of the few states that actually sent replacements to its regiments in the field with the armies.