grand army of the republic
patriotic organization of American Civil War veterans who served in the Union forces, one of its purposes being the "defense of the late soldiery of the United States, morally, socially, and politically." Founded in Springfield, Ill., early in 1866, it reached its peak in membership (more than 400,000) in 1890; for a time it was a powerful political influence, aligning nearly always with Republican policy. In 1956 it was dissolved; its records went to the Library of Congress, Washington, D.C., and its badges, flags, and official seal to the Smithsonian Institution.
Learn more about Grand Army of the Republic with a free trial on Britannica.com.