He took part in the capture of the German Merchant raider SMS Cormoran in April 1917, when United States declared war on Germany.

[3] Upon his return to the United States, Pickett served for a brief period at the Marine barracks at Puget Sound Navy Yard in Bremerton in Washington.

[4] Pickett's regiment was attached to the 5th Marine Brigade under Brigadier General Eli K. Cole and ordered to France in October 1918.

He was promoted to major on July 28, 1925, and assigned for duty with the Quartermaster Department under Brigadier General Charles L. McCawley.

He returned to the United States in January 1930 and served at Marine Corps headquarters until July 1935 during which time he was promoted to the rank of lieutenant colonel, on May 29, 1934.

He then served at Marine Corps installations at Quantico and San Diego and completed a course at Army Coast Artillery School at Fort Monroe in Virginia.

[1] Because of the increasing danger of Japanese expansion in Pacific during 1939, the United States Congress established a special board under Admiral Arthur J. Hepburn.

[5][6][7] In May 1940, Pickett supervised the deployment of the 3rd Defense Battalion under Lieutenant Colonel Robert H. Pepper on Hawaii and ordered one of his 3-inch anti-aircraft artillery detachments to defend Midway Atoll.

Bone also arrived on Hawaii and Pickett ordered immediately some of his detachments to the defensive positions on Palmyra and Johnston Atoll.

[1][9][10][11] Following the end of the war, Pickett remained in command of the Troop training Unit at Coronado until July 1946, when he was succeeded again by Major General LeRoy Hunt.

Pickett then retired from the Marine Corps after 33 years of active service and was advanced to the rank of major general for having been specially commended for performance of duty in actual combat.