On August 5, 1917, Blanding was called up to serve in
World War I, where he commanded the 53rd Brigade, part of Major General
John F. O'Ryan's
27th Division, O'Ryan's roughnecks as it was often called, as a
brigadier general. In France, he commanded the 185th Infantry Brigade, which included the
370th Infantry Regiment from Illinois. After hostilities ceased, he was awarded the Army Distinguished Service Medal, the citation for which states the following: He was discharged from the Army on March 1, 1919, after which he resumed his service to the Florida National Guard. ==Post World War I==