On September 24, 1919, 42 World War I veterans from Jefferson Davis Parish in Louisiana signed the Application for Post of American Legion. They were: Leon Alcock, Viron L. Barnhill, A. J. Bertrand, Otto Bollich, Eli G. Breaux, F. N. Cart, Howard B. Cary, Louis E. Cole, Ward A. Davis, Willard Demmon, Edward Fallect, Robert Frey, Marius Fuselier, John D. Hathorn, Israel L. Hebert, Clebert Hollier, Frederich A. Koll, Henry H, Koll, Peter W. Koll, Glenn W. Lang, Ozena LeBlanc, Eulice Lejeune, Marco Lukinovich, John J. McHugh, Jr., Earl H. McMillan, Earl C. Miller, Minos D. Miller, Roy S. Miller, Gus P. Modlish, L. A. Moore, Harry Noggle, Leo J. Nohe, S. P. Quigley, Jules Reaud, Robert B. Ricker, C. F. Stakes, Marvin Stansbury, Frank M. Taylor, Herbert Tietje, Louis Z. Toups, Gilbert Wiltz, and L. Woodyard.
They elected to name their Post after Captain James O. Hall, who had been a member of the First Separate Troop, Louisiana Cavalry, from Jennings before the troop was called into service during World War I. Captain Hall died in service to his country during the war. According to American Legion National Headquarters, the official charter date for James O. Hall Post 19 of the American Legion, Department of Louisiana, is October 10, 1919. However, Post members began meetings and started conducting activities shortly after they submitted their application in September of 1919. Roy S. Miller served as the first Post Commander. Miller served as an officer with the First Separate Troop, Louisiana Cavalry when the unit was activated and deployed to France for service in World War I. Seven of the 42 founding Post members were with this cavalry troop. The picture above shows Miller in front of his soldiers by the speakers stand during the welcome home celebration conducted for the cavalry unit in Jennings on May 13, 1919.