Doe was promoted to
first lieutenant on 1 July 1916 and
captain on 15 May 1917, a few weeks after the
American entry into World War I. From May to August 1917 he was stationed with the 11th Infantry at
Fort Oglethorpe, Georgia. He attended a
machine gun training course at
Fort Sill before assuming command of the 15th Machine Gun Battalion, part of the newly created
5th Division, in December 1917. In April 1918, he sailed for
France. Promoted to the temporary rank of
major on 17 June 1918, Doe served as the 5th Division's Machine Gun Officer before assuming command of the 14th Machine Gun Battalion, also of the 5th Division, in July. As such, he participated in the
Battle of Saint-Mihiel and the subsequent
Meuse–Argonne offensive, the largest battle in the
history of the United States Army, where he was wounded, although his gallantry earned him the
Silver Star. In November 1918, the same month the
Armistice with Germany brought the war to an end, Doe organised and became an instructor at the Army Machine Gun School at
Langres. He was an instructor at the
II Corps Schools, and a student at the Artillery Center. In June 1919 he joined the 61st Infantry, returning to the United States with it in June 1919. ==Between the wars==