In September 1934, he was attached to the Marine detachment aboard the cruiser USS Augusta under then-Captain Chester W. Nimitz and took part in cruises to the Dutch East Indies and Australia.

He was ordered to the course at Ordnance Field Service School at Raritan Arsenal in Metuchen, New Jersey, during September 1939 and graduated in December of that year.

Larson was succeeded by his deputy, first lieutenant Ronald R. Van Stockum, and ordered back to Quantico in February 1942 and assigned to the staff Commandant of Marine Corps Schools, Brigadier General Samuel M. Harrington.

[1] He was ordered to the Pacific area at the beginning of April 1944 and was attached to 1st Provisional Marine Brigade at Guadalcanal, which had just been activated under the command of Brigadier General Lemuel C. Shepherd.

The 6th Division underwent "rugged" training on Guadalcanal between October 1944 and January 1945 and was attached to the III Marine Amphibious Corps for the Battle of Okinawa.

[4] Larson landed on Okinawa at the beginning of April 1945 and distinguished himself again in coordinating the supply of material and ammunition to the front line units.

Colonel Roberts was killed by a Japanese sniper on June 18 and Larson assumed the command of the regiment as senior officer present.

[1] He resumed his duties as an executive officer on June 22, 1945, and spent the next several months on Guam, where the 6th Marine Division underwent preparations for future combat deployment.

[7] Larson returned to the U. S. in August 1946 and received the Chinese Special Breast Order of Yun Hui for his service during the repatriation of Japanese.

This group was tasked with the development of the recommendations on how the MAGTF should evolve structurally to meet the challenges of atomic warfare and new technologies such as helicopters and jet aircraft.

The members of the group were Thomas J. Coolley, John P. Condon, Joseph N. Renner, Carson A. Roberts, Samuel R. Shaw, George R. E. Shell, Eustace R. Smoak, William J.

[8][9] During July 1955, Larson was transferred to the California and appointed deputy commander of Camp Pendleton under Major General George F. Good.

[1] Following his return, Larson served briefly as deputy chief of staff for research and development, before being appointed director of personnel in August 1958.