A Company consisted of the Detroit Light Guard.

The 1st Michigan was the state's only three-month regiment, raised in response to President Abraham Lincoln's initial call for 75,000 troops in April 1861.

On June 1, 1861, the unit participated in the Battle of Arlington Mill alongside the 11th New York Infantry Regiment.

Their first and last major battle during their three months of service was on Jun 21st Battle of Bull Run where they would suffer 117 casualties,[1] their commander Colonel Willcox and Captain Withington being taken poisoner (released later due to a poisoner exchange), and the loss of their Battle flag (it was returned to the state and regiment 6 years later on July 4, 1866)[2] The regiment was mustered out on August 7, 1861.

This article about a specific military unit of the American Civil War is a stub.