The Marine Corps League, formed in 1923 by members of what had been the Marine Corps Veterans Association, assimilated more than 40 existing Marine oriented organizations that sprang up following the end of World War I. Comprised largely of veterans of the fierce fighting between the Fifth and Sixth Marine Regiments and the Germans, these returning veterans of the Great War ("the war to end all wars") were called "Teufelhunde" by their German adversaries, literally meaning "Dogs of the Devil," or as we now know, DEVIL DOGS. Legend has it that, because our Marines were so under-supplied during the battle of Belleau Wood; that when they engaged the Germans in hand-to-hand combat, they bit them!

These battle-hardened Marines who, for all time, earned for ensuing generations, the title "Devil Dog" more than 75 years ago on 6 June 1918, were a part of the American Expeditionary Forces (AEF) commanded by General John J. "Black Jack" Pershing. They had set sail on 14 June 1917 under orders from Major General Commandant George Barnett as a "Force in Readiness". At the time, the total strength of the Marine Corps, worldwide, stood at 511 officers and 13,214 enlisted men. Landing in Europe, they included two-time Medal of Honor recipient First Sergeant Dan Daly. Colonel A. W. Catlin, a Medal of Honor recipient at Vera Cruz, was evacuated from Belleau Wood after having been shot by a German sniper. Gunnery Sergeant E. A. Janson (who served in the Corps as Charles Hoffman) earned the first Marine Medal of Honor for saving his command, the 49th Company. At the end of the battle for Belleau Wood, 1,062 Marines lay dead. The French General commanding the Sixth Army ordered that Belleau Wood (Bois de Belleau) be henceforth known as "Bois de la Brigrade de Marines". Seven Marines would ultimately be awarded the Medal of Honor for their actions during World War I.

Following the establishment of the Marine Corps League, the leadership of the League decided that the delgates assembling in convention needed some time during their serious deliberations to "blow off steam". As a result, the Military Order of Devil Dogs was organized and created in 1939, in Boston, Massachusetts; and granted a charter as a subsidiary organization of the Marine Corps League on 19 March 1940. From those early years, the Military Order of Devil Dogs (The Order) has grown to a strength of over 3,000 members.