Daniel N. Keeler was a private thruout his service in the 8th Missouri Volunteer Infantry.   He was wounded at Fort Donelson, Tennessee, and was medically discharged at Jefferson Barracks in St. Louis.

GAR Post #152 in Melrose (now Wildwood), Missouri, was named after Daniel Keeler.   The photo above, taken by Cher Pertovic, shows the Kreienkamp Store with the D. N. Keeler GAR Post attached.

The marker above is at the DN Keeler GAR Post in Wildwood, Missouri; the marker was dedicated in 2001.   Photo is from J. D. Avery, The Civil War Undertaker

From WIKIPEDIA:
The Grand Army of the Republic (GAR) was a fraternal organization composed of veterans of the Union Army who had served in the American Civil War.   The GAR was among the first organized interest groups in American politics.   It was succeeded by the Sons of Union Veterans of the Civil War (SUVCW).