 Holdridge would remain with Training Commands for the rest of his Army career.He was promoted to Colonel and headed the Plans Training Division of the Adjutant General's Department at the onset of World War II, and was assigned as Commandant of the Adjutant General School at Fort Washington, Maryland, on January 19, 1942.He also became Director, Schools Training, Army Administration Schools, and was promoted to Brigadier General in early 1942.