He was then assigned to the newly created 77th Infantry Division as chief of staff, becoming a colonel by February 3, 1918, and then a brigadier general on June 25, 1918.

In September and October of that same year he led the 8th Infantry Brigade in the first phase of the Meuse-Argonne Offensive, for which he was later awarded the Army Distinguished Service Medal on July 9, 1919, the citation for which reads: The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Brigadier General Ewing E. Booth, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I.

General Booth commanded, with great ability and gallantry, the 8th Infantry Brigade in the operations which forced the reluctant enemy to evacuate Bois-du-Feys, Bois-de-Malaumont, Bois-de-Peut-de-Faus, and Bois-de-Foret in September and October 1918.

On January 8, 1920, he was made deputy allied high commander in Armenia, and served in this capacity until June 30.

[1] On July 1, 1920, Booth reverted to the rank of colonel of cavalry and returned to the United States to act as the assistant commandant of the Army's General Service School.

Booth was then commandant of the United States Cavalry School at Fort Riley, Kansas from July 1, 1925, to May 1, 1927, during which time he met and posed for a picture with Will Rogers.