The First Michigan Cavalry commenced recruiting August 21, 1861, at Camp Lyon, near Detroit, the place of rendezvous, the organization of the regiment being under the direction of Thornton F. Brodhead, who had been appointed its colonel. It was mustered into service on the thirteenth of September following with one thousand one hundred and forty four men on the rolls.

It left Camp Lyon on the twenty ninth of September for Washington, laying in camp at Frederick, Maryland, a considerable portion of the winter, its principal service being on the upper Potomac, in the Shenandoah Valley and near the eastern slopes of the Blue Ridge

In February 1862, General Banks was in charge of the union troops on the Maryland side of the Potomac, this command composing part of his force.

On the twenty fourth of February, the rebels were followed to Cedar Creek, being in sight and taking advantage of every favorable point to check the advance. Colonel Brodhead reconnoitered as far as Strasburg, but fell back during the night across the creek.

During its first year of service ending at Bull Run, August 1862, it lost thirty men on the field, sixty died of disease and lost one hundred and seventy.

From Winchester, Virginia to its garrison of Camp Douglas and Fort Bridger, Utah, March 10, 1866, its long term of service was characterized by gallant conduct. The conduct of the war department in its connection with the last service of this regiment was opposed in every point of justice and honor. Its consolidation with the Sixth and Seventh Michigan Calvary regiment as the First Regiment Michigan veteran Cavalry, November 10, 1865m and the imposition of continued service in the west were opposed to all the articles of enlistment.

The regiment was mustered out at Salt Lake City, Utah on March 10, 1866 also paid off and disbanded there.