Upon graduation in May 1941, he joined the 1st Marine Aircraft Wing. He accompanied the Wing to the South Pacific in September 1942, where he participated in the Battle of Guadalcanal as the chief of staff for, then major general, Roy Geiger. He would become commander of the Cactus Air Force on November 7, 1942 and lead the men through the lowest point in the campaign until he turned the command over to Brigadier General Francis P. Mulcahy on December 26, 1942.