Major General John Eugene McMahon (December 8, 1860 – January 28, 1920) was a United States Army officer who served in numerous conflicts, most notably in World War I, where he commanded the 5th Division.

degree, and he entered the United States Military Academy (USMA) at West Point, New York, and graduated number eleven of seventy-seven in the class of 1886.

[2] Several of his classmates included men who would, like McMahon himself, eventually rise to general officer rank, such as John J. Pershing, Charles T. Menoher, Walter Henry Gordon, Edward Mann Lewis, Mason Patrick, Julius Penn, Avery D. Andrews, George B. Duncan, Ernest Hinds, William H. Hay, James McRae, Lucien Grant Berry and Jesse McI.

In July 1899 he became a major in the 31st Infantry and, following the end of the Philippine–American War which he briefly participated in, McMahon was mustered out in June 1901, after having been made a captain of Artillery in January of that year.

[4][5] In late August 1917, almost five months after the American entry into World War I, McMahon was promoted to the temporary rank of brigadier general and was assigned to command the 160th Field Artillery Brigade, part of the 85th Division.

[4] In order to ready itself for combat against the Imperial German Army, the division began training in the Anould and Saint-Dié sectors, near the Vosges mountains.