The 3rd Wisconsin assembled at Camp Hamilton, in Fond du Lac, Wisconsin, and mustered into Federal service on June 19, 1861.

The 3rd Wisconsin Infantry was a part of Gen. Nathaniel Banks' army during Jackson's Shenandoah Valley campaign of 1862.

Later in the year, the 3rd Wisconsin took part in the fighting around the Cornfield during the Battle of Antietam.

The regiment participated in the Grand Review of the Armies on May 24, 1865, and then mustered out at Louisville, Kentucky, on July 18, 1865.

[1] The regiment lost 9 officers and 158 enlisted men killed in action or who later died of their wounds, plus another 2 officers and 113 enlisted men who died of disease, for a total of 282 fatalities.