The 126th Infantry Regiment has been in active military service since 1855. The regiment began as militia companies in Grand Rapids. They provided the core of the Third Michigan Infantry Regiment, which served in the Civil War. After the war, the companies were reorganized as part of the Second Infantry, Michigan State Troops, the forerunner of the Michigan National Guard. When the U.S. entered World War I in 1917, the 126th was organized and assigned to the Thirty-second "Red Arrow" Division,
which was honored by the French with the Croix de Guerre
for gallantry shown in the 1918 Oise-Aisne offensive. During World War II the 126th was part of the Thirty-second Division seeing action in New Guinea and the Philippines. During the war the regiment saw 654 days of combat, more than any other American unit.
The 126th Infantry Regiment has demonstrated the value of the National Guard during peacetime. Michigan National Guard units have been mobilized to assist civil authorities during strikes, riots and natural disasters. In 1873 the 126th, then the Second Regiment, quelled rioting at the Muskegon County Jail in its first peacetime role. The regiment was also mobilized during a 1909 railroad strike in Durand, the 1913 Upper Peninsula copper strike and the 1937 General Motors Sit-Down Strike
in Flint. In July 1967 the regiment was mobilized to maintain peace during the Detroit riots. Natural disasters that required the regiment's assistance included an April 1956 tornado in the Grand Rapids area and a West Michigan blizzard in January 1878.