Bald's ambulance company was originally designated Ambulance Company 3 of the Pennsylvania National Guard. The company barracks were located in the Phi Sigma Kappa Pi Chapter fraternity house on the campus of Franklin and Marshall College. In September 1917, the company moved to Camp Hancock near Augusta, Georgia for further training. The unit was re-designated as Ambulance Company 111, 103rd Sanitary Train, attached to the 28th Division of the American Expeditionary Force. In May 1918 the company left for Camp Mills in Long Island, New York where they stayed before crossing the Atlantic Ocean and landing in England on June 1. The unit reached France on June 14, 1918. Bald's ambulance unit went into action on July 15, 1918, in the Second Battle of the Marne. He also participated in the Oise-Aisne Offensive, and Meuse-Argonne Offensive. Bald was promoted to private first class in May 1918. Bald was discharged at Camp Dix, New Jersey on July 12, 1919.