In 1866 northern Civil War veterans organized the Grand Army of the Republic to fight for veterans' pensions and other benefits. Michigan's first chapter was formed the next year. National membership peaked in 1890 with 409,489 men, while Michigan's rolls crested in 1889 with more than 21,000 members. In its heyday, the G.A.R. was a powerful political pressure group. The society also provided food and clothing for indigent widows and orphans. The last state encampment was held in 1948.
Marshall's Civil War veterans organized a Grand Army of the Republic chapter in 1883. They built this handsome red-brick structure as their headquarters in 1902. It was named for Marshall's Corporal Calvin Colegrove, color-bearer for the Michigan First Infantry, who was killed at the first Battle of Bull Run on July 21, 1861. The memorial hall, built at a cost of $3,000, served C. Colegrove Post No. 166 until the late 1930s. In 1977 the Marshall Historical Society purchased it for one dollar to house its archives.