The organization wielded considerable political clout nationwide; between 1868 and 1908, no Republican was nominated to the presidency without a GAR endorsement.
The GAR was active in pension legislation, establishing retirement homes for soldiers, and many other areas which concerned Union veterans. Their influence led to the creation of the Old Soldiers' Homes of the late 19th century which evolved into the current United States Department of Veterans Affairs.
In 1868, General Order #11 of the GAR called for May 30 to be designated as a day of memorial for Union veterans; originally called "Decoration Day," this later evolved into the U.S. national Memorial Day holiday.
In the 19th century, there was some controversy over the fact that the membership badge of the GAR closely resembled the Army's version of the Medal of Honor, causing confusion and animosity among veterans. The issue was resolved with a re-design of the latter in 1896.
The organization held an annual "National Encampment" every year from 1866 to 1949; the last member, Albert Woolson, died at the age of 109 in 1956.
The GAR also generated several auxiliary organizations, some of which are still extant. A comparable organization for Confederate veterans was the United Confederate Veterans (q.v.).
A successor organization is the Sons of Union Veterans of the Civil War (SUVCW).