The first GAR Post was organized at Decatur, Illinois on April 5, 1866 by Dr. B. F. Stephenson of Springfield, Illinois. Local Posts were first formed in Oklahoma around 1889.
In Oklahoma, the Posts held annual three-day encampments at various locations around the state. Their purpose was to promote patriotism in the observances of Memorial Day (formerly called Decoration Day) and Flag Day. The GAR members formed brass bands and performed marching skills in various public parades and events.
Objectives of the GAR were therefold: Fraternity among Union veterans; Charity for needy veterans, widows, and orphans of veterans; and Loyalty to the United States and its Constitution.
Organization of the GAR was patterned along the lines of their former military services. They had Commanders, Senior and Junior Vice-Commanders, Chaplains, Medical Directors, and Quartermasters.
Other closely associated groups to the GAR were the Women's Relief Corp (WRC), Sons of Union Veterans, and the Ladies of the GAR.
Historian Mahion G. Erickson of Stillwater, Oklahoma published an comprehensive article on Oklahoma GAR records in the January/February 1992 issue of Heritage Quest Magazine. He stated that some records have been preserved and can be found in the Archives and Manuscript Division of the Oklahoma Historicial Society in the Wiley Post Building at the State Capital in Oklahoma City. The following records are available for viewing:
Erickson said The Journal of the Grand Army of the Republic in Oklahoma, Volume I (1893-1909) and Volume II (1910-1922) are available at the Oklahoma Historical Society Library on the second floor of the Wiley Post Building in Oklahoma City.