The 21st Michigan Infantry Regiment was organized in Ionia and Grand Rapids in 1861, drawing recruits from the Fourth Congressional District, and mustered on September 9, 1862.  The Fourth Congressional District was comprised of the following counties:  Barry, Ionia, Montcalm, Kent, Ottawa, Muskegon, Oceana, Newago, Mecosta, Mason, Manistee, Grand Traverse, Leelanaw, Manitou, Osceola, Emmet, Mackinac, Delta and Cheboygan.  When mustered, the 21st had an enrollment of 1,000 officers and men.

The Regiment left Michigan for Louisville, Kentucky on September 12, 1862.  The Regiment was attached to Brigades and Divisions as follows:  37th Brigade, 11th Division, Army of the Ohio, September, 1862; 37th Brigade, 11th Division, 3rd Corps, Army of the Ohio, to November, 1862; 1st Brigade, 3rd Division, Right Wing 14th Army Corps, Army of the Cumberland, to January, 1863; 1st Brigade, 3rd Division, 20th Army Corps, Army of the Cumberland, to October, 1863; 1st Brigade, 2nd Division, 4th Army Corps, Army of the Cumberland, to November, 1863; Engineer Brigade, Army of the Cumberland, to November, 1864; and 2nd Brigade, 1st Division, 14th Army Corps, to June, 1865.

During the course of the war, the 21st Regiment lost 377 men:  3 officers and 80 enlisted men were killed or mortally wounded.  3 officers and 291 enlisted men died from disease.  The Regiment was mustered out on June 8, 1865. 

14 Chester Township men volunteered withCompany E of the 21st Regiment.  5 of these 14 men gave their lives during the war.  The table below gives the names, home residence and ages of the men in Company E.  Those men in red were from Chester Township.  Chester Township men with a diamond to the right of their name gave their lives during the war.