Eligibility to Membership – Soldiers and sailors of the United States Army, Navy or Marine Corps, who served between April 12th, 1861, and April 9th, 1865, in the war for the suppression of the Rebellion, and those having been honorably discharged there from after such service, and of such State regiments as were called into active service and subject to the orders of the United States General Officers, between the dates mentioned, shall be eligible to membership in the Grand Army of the Republic. No person shall be eligible to membership who has at any time borne arms against the United States. (Rules and Regulations Grand Army of the Republic, Chapter I, Article IV)

The Grand Army of the Republic (GAR), was created by Dr. B.F. Stephenson of Springfield, Illinois, for Union veterans of the Civil War. He and some friends organized the first Post (local chapter) in Decatur, Illinois on April 6, 1866, the anniversary of the Battle of Shiloh. The first annual encampment (convention) of the Department of Illinois was held in July and the first national encampment convened in Indianapolis that November.

In 1948, with only 28 members remaining in twelve posts, it was agreed that the 1949 National Encampment would be the last. On August 28, 1949, six of the surviving sixteen members, ranging in age from 99 to 108, returned to Indianapolis for the 83rd and final encampment. Albert Woolson of Duluth, MN, the last survivor, died August 2, 1956, at the age of 109, and the organization was officially disbanded in October 1956.

Missouri's first post was organized in Kirksville, October 1, 1866, and was named for Corporal Hervey Dix, the first Union soldier to be killed in Adair County. Later described by GAR historian Robert R. Beath as "one of the most efficient Posts in the interior of the state," it lasted only a couple of years before becoming the victim of internal political strife. When reorganized in 1882, it was designated Post Number 22 by the Department of Missouri which had been fully organized by twenty-one other posts during its hiatus.

During its active years, Corporal Dix Post helped establish posts in several Adair County communities including Brashear, Millard, Shibley's Point and Sublette. Locally, they sponsored annual soldiers' reunions and staged one of the earliest post-war battle reenactments when they recreated the Battle of Kirksville on the site of that engagement in 1868. In the mid 1910's they raised funds for and erected a monument to fifteen Confederate soldiers who were executed the day after the Battle of Kirksville on charges of parole violation. Decoration of the monument was part of the Dix Post's Memorial Day observances each year until it disbanded.

With only a few elderly members still living, the Post voted to disband in the Spring of 1934. The records, including membership applications, were given to the library at Northeast Missouri State Teachers College (now Truman State University) along with some documents from the local chapters of the Woman's Relief Corps and the Sons of Veterans.

The Woman's Relief Corps, for wives and female relatives of Union veterans, was organized on a national level in 1883. The Department of Missouri held its first encampment in 1885 and Kirksville's Corporal Dix Post Number 14 was organized later that year. The ladies also disbanded in the Spring of 1934.

The Sons of Veterans, United States of America, an organization for men whose fathers had been Union soldiers, resulted from the 1886 merging of two rival groups, both of which had been created by GAR posts. Kirksville Camp Number 119 was chartered in May 1889 but apparently did not last much longer than a year. The men reorganized in 1896 as Capt. T.C. Harris Camp Number 41. There is no record of the camp's demise, but indications are it lasted no longer than its predecessor; the last entry in the Membership Register is dated one month after the Charter was issued.