William Denton entered recruit training at Marine Corps Recruit Depot, San Diego, in June 2004, where he was screened and selected for the Presidential Support Program. Upon completion of recruit training, Private First Class Denton reported to the Infantry Training Battalion, School of Infantry–West, and earned the Military Occupational Specialty of Infantry Rifleman. He subsequently attended Basic Security Guard School at Marine Security Force Training Company.
Following graduation in February 2005, Lance Corporal Denton reported to Marine Barracks Washington, D.C. (8th and I), where he was assigned to Guard Company. He later received orders to the White House Communications Agency, where he served as a sentry and Corporal of the Guard, and supported official presidential visits to Vietnam and China. Upon completion of his tour, he was awarded the Presidential Support Badge and promoted to Corporal in June 2007. Returning to Marine Barracks 8th and I, he served as Training Noncommissioned Officer and Sergeant of the Guard. He was promoted to Sergeant in April 2009 and separated from active duty in June 2009.
In February 2010, Sergeant Denton affiliated with the Marine Corps Reserve and was assigned to Anti-Tank Training Company. He later attended Infantry Training Battalion, School of Infantry–East, earning the Anti-Tank Missileman designation. Assigned to 1st Battalion, 25th Marines, he volunteered for mobilization in April 2011 in support of Operation Enduring Freedom 11-1. During deployment to Afghanistan, he served as a Squad Leader and Vehicle Commander in a Mobile Assault Platoon.
Following his return in June 2012, Sergeant Denton was assigned to 3rd Battalion, 24th Marines as a Section Leader. In July 2013, he attended the Reserve Staff Noncommissioned Officer Academy in Quantico, Virginia, and was promoted to Staff Sergeant in August 2013. He subsequently served as a Section Leader with 3rd Battalion, 25th Marines. In May 2016, he earned a Bachelor of Arts in Homeland Security from American Military University. In July 2016, he assumed duties as Platoon Sergeant for Anti-Tank Training Company, 25th Marine Regiment.
Staff Sergeant Denton attended the Anti-Armor Leaders Course in July 2017. He was promoted to Gunnery Sergeant in June 2019 and mobilized in support of the Unit Deployment Program 20-1, serving as Platoon Sergeant for Combined Anti-Armor Team (CAAT) Platoon II. During this deployment, he participated in training operations in Okinawa, Camp Fuji, and the Republic of Korea. In March 2020, he assumed duties as Platoon Sergeant for an amalgamated CAAT platoon of 75 Marines and Sailors. Upon demobilization in June 2020, he served as Chief Instructor for Anti-Tank Training Company.
In June 2023, Gunnery Sergeant Denton was frocked to First Sergeant and assigned to Support Company, 4th Law Enforcement Battalion in Albuquerque, New Mexico, in August 2023. In January 2026, he assumed duties as the Unit Senior Enlisted Leader for Anti-Tank Training Company, Broken Arrow, Oklahoma.
First Sergeant Denton’s personal decorations include the Navy and Marine Corps Commendation Medal, Navy and Marine Corps Achievement Medal (with Gold Star in lieu of second award), and the Presidential Support Badge, in addition to numerous Certificates of Commendation and Letters of Appreciation.
In his civilian capacity, First Sergeant Denton serves as a Supervisory Natural Resources Specialist with the U.S. Army Corps of Engineers.