The Military Order of the World Wars was founded in 1919 by Officers who had served under General of the Armies John J. “Black Jack” Pershing to perpetuate those ideals for which they had fought the Great War. In fact, the Order was originally named the American Officers of the Great War. It was incorporated by an act of Congress on January 27, 1919 . The Order was intended to be the successor to the Society of the Cincinnati for George Washington's Officers of the Continental Army and the Military Order of the Loyal Legion of Federal Officers who served in the Civil War. With an initial membership fee of $5.00, the founders set about the task of recruiting a membership nucleus, a "Committee of 1000," consisting of men across the country and from outside the Continental United States in Alaska , Hawaii , Canada , Cuba , and Europe .

One of the lasting accomplishments of the 1920 convention was the adoption of the Preamble to the Constitution and Bylaws. The Preamble was written by Captain Francis B. Grevemberg, a Charter Member of the New Orleans Chapter, who drafted the document on the back of an envelope while traveling by train to the convention. His handwritten draft now hangs proudly on a wall in the Order's National Headquarters. Its wording has been changed slightly during the intervening decades. Most notably, a precept has been added concerning patriotic education, but, otherwise, the Preamble's direction and clarity of purpose remain constant. The Preamble remains the foundation upon which the Order has been constructed.

Preamble:

To cherish the memories and associations of the World Wars waged for humanity;
To inculcate and stimulate love of our Country and the Flag;
To promote and further patriotic education in our nation;
Ever to maintain law and order, and to defend the honor, integrity and supremacy of our National Government and the Constitution of the United States;
To foster fraternal relations among all branches of the armed forces;
To promote the cultivation of Military, Naval and Air Science and the adoption of a consistent and suitable policy of national security for the United States of America;
To acquire and preserve records of individual services;
To encourage and assist in the holding of commemorations and the establishment of Memorials of the World Wars; and
To transmit all these ideals to posterity; under God and for our Country, we unite to establish The Military Order of the World Wars.