Jan. 16, 1952: Joined USMC in Minneapolis, MN.
Jan-Apr. 1952: Assigned to 6th Rec. Training Bn., Marine Corps Recruiting Depot, San Diego, CA.
Began USMC service as a trained replacement infantryman, later took specialty training as machine gunner (MOS: 0311) at Camp Joseph H. Pendleton.
Apr. 1952-Apr. 1953: Assigned to Co. "D" 2nd Bn. 9th Regt. 3rdMarDiv., Camp Pendleton, San Diego, CA.
May 1953: Arrived ROK assigned to 3rd Section MG, 3rd Plt., Co. "F", 2nd Bn. 7th Regt. 1st MarDiv. Joined unit at Corps Reserve base Camp Indian Head north of Panmunjom, Gyeonggi Prov. ROK.
Jul. 7- Jul. 27, 1953: Time spent on frontline.
Jul. 7, 1953: His unit relieved the Turkish Bde. at Outposts Berlin, East Berlin and Boulder City.
Participated in the Battle of Samichon River. During two nights of the battle Fox Co. took 70% casualties.
Jul. 25, 1953: SSGt. Ambrosio Guillen was killed and posthumously awarded the Medal of Honor.
At some point took R&R for 5 days and 5 nights in Kyoto, Kyoto Prefecture, Japan and was grealty impressed by the beauty of the ancient Japanese capital.
Following the Armistice (Jul. 27, 1953), was assigned to 1st Provisional DMZ Police Co., 1st MarDiv. responsible for patrolling the DMZ and overseeing POWs from DPRK and PRC who refused to be repatriated.
Jan. 1954: By this time he was assigned to H&S Co., 5th Marines, 1st MarDiv.
Aug. 1954: Returned USA via Treasure Island, San Francisco, CA. Spent last remaining months in the USMC at Camp Pendleton.
Jan. 16, 1955: Separated from USMC.