The Fourth Michigan Infantry was recruited from the southern tier of counties of Michigan State, being organized by Colonel Dwight A. Woodberry at Adrian. Like many other Michigan regiments its shared border with Canada insured the addition of many Canadian recruits and the shared border with Canada West (Ontario) facilitated the active recruitment by Michigan regiments. The 4th Michigan Regiment was composed of the "Peninsular Guard" (COMPANY ‘C’) of Sturgis, the "Barry Guard" of Ann Arbor, the "Smith Guard" of Monroe, the "Trenton Volunteers" of Trenton, the "Dexter Union Guard" of Dexter, the "Hudson Volunteers" of Hillsdale, the "Grosvenor Union Guard" of Jonesville, and the "Tecumseh Volunteers" of Tecumseh. The organization of the Regiment was completed at its rendezvous in Adrian, and then mustered into the United States service for three years on June 20, 1861.
