The Regiment was immediately sent west to help Minnesota deal with the Sioux uprising.

Wisconsin was part of the Army's newly formed Department of Dakota that had been created to deal with the problem.

The Department was Headquartered at St. Paul under the command of Major General John Pope.

[3] In a January 1863 letter to his sister, Union soldier Chauncey H. Cooke, a private from the regiment's Company G, gave his reasons for fighting for the Union in the war, stating that "I have no heart in this war if the slaves cannot go free.

The 25th Wisconsin suffered 3 officers and 46 enlisted men killed in action or who later died of their wounds, plus another 7 officers and 402 enlisted men who died of disease, for a total of 460 fatalities.