Sergeant Major Harrison graduated from Myrtle Beach High School and enlisted in the Marine Corps in August 2001 and completed recruit training at Marine Corps Recruit Depot, Parris Island SC. Private (PVT) Harrison graduated recruit training from Fox Company on November 17th, 2001. After graduation, PVT Harrison reported to Marine Combat Training aboard Camp Geiger, North Carolina, where he was meritoriously promoted to Private First Class (PFC) upon completion of Marine Combat Training in December of 2001.
Upon completion of Aviation Structural Mechanic School, LCpl Harrison deployed with HMH-464 to Operation Iraqi Freedom from Jan. 2003 to Aug. 2003 during which he was promoted to Corporal (Cpl). Following the deployment, Cpl Harrison attended the resident Corporal's Leadership Course. Upon graduating fourth in the class and receiving the Gung Ho Award for showing motivation above and beyond that of his peers, Cpl Harrison then attached to HMM-162 to deploy with the 26th Marine Expeditionary Unit (MEU). During this deployment he gained the MOS qualification of Collateral Duty Inspector (CDI). On Feb.1st 2005, while deployed with the 26th MEU, Cpl Harrison was promoted to Sergeant (Sgt).
Immediately following the deployment's return, in December 2005, Sgt Harrison reported to Drill Instructor (DI) School aboard Marine Corps Recruit Depot (MCRD) Parris Island. In March of 2006, Sgt Harrison graduated from DI School and was assigned to Second Battalion, Fox Company. On July 1st of 2007, Sgt Harrison was promoted to Staff Sergeant (SSgt). His tour aboard the Parris Island Recruit Depot included graduating nine platoons. He was also appointed the Depot Dental Liaison and held the positions of Headquarters Company 1stSgt and Battalion S3 Chief. SSgt Harrison attended the Staff Non-Commissioned Officer (SNCO) Career Course in Jan. 2010. In April of 2010, after completion of a successful tour as a Marine Corps Drill Instructor, SSgt Harrison was assigned to Heavy Marine Helicopter Squadron 464 (HMH-464).
SSgt Harrison was appointed the Airframes Division Chief upon checking into HMH-464 and deployed as the Detachment (DET) Airframes Division Chief in January of 2011. SSgt Harrison fulfilled many billets while deployed to include Body Composition Program Chief, Collateral Duty Quality Assurance Representative (CDQAR), and Chief Instructor / coordinator for Camp Lemonier, Combined Joint Task Force, Horn of Africa's sponsored Corporal's Course.
In September 2011 SSgt Harrison was appointed the CH53E Airframes DET SNCOIC assigned to VMM-261 Reinforced (REIN) and deployed with the 24th Marine Expeditionary Unit. SSgt Harrison led his Division aboard the USS New York and USS Iwo Jima, and in various land-based operations throughout the 5th Fleet area of operations. At the end of the deployment, He became the DET SNCOIC. SSgt Harrison obtained his Black Belt qualification in the Marine Corps Martial Arts Program and instructed various classes in multiple Corporal's Courses instructed while deployed. Upon the MEU's return in January 2013. SSgt Harrison requested, received, and accepted orders to Iowa State University as the Assistant Marine Officer Instructor.
SSgt Harrison served as a Sergeant Instructor for Golf Company 3rd Platoon at Officer Candidates School while in transit to Iowa State University from May 8th through August 17th, 2013. Over the summer he completed two increments of Officer Candidate training. SSgt Harrison received the outstanding Drill Instructor award for his untiring efforts, leadership by example and exemplary performance of duty in the education and development of Marine Corps Officer Candidates. SSgt Harrison completed one increment as a Sergeant Instructor for Lima Company 4th platoon while TAD to Officer Candidate School from June 25 through August 16th 2014.
In January 2015, SSgt Harrison received the Assistant Marine Officer Instructor of the year Naval Reserve Officers Training Corps for the North central Region award presented by USAA along with receiving the National Assistant Marine Officer Instructor of the year award for 2014. SSgt Harrison was promoted to Gunnery Sergeant (GySgt) July 1st 2015 where he continued to serve as the Assistant Marine Officer Instructor and also held the billet of Marine Officer Instructor in the billet vacancy.
In August 2016, GySgt Harrison was appointed the Airframes Division Chief upon checking into HMH-464, fulfilling many billets throughout the unit to include Collateral Duty Quality Assurance Representative (CDQAR) and Equal Opportunity Representative. In February 2019, GySgt Harrison was frocked and accepted orders to Marine Corps Detachment Fort Leonard Wood Missouri. There he served as the Motor Transport Instruction Company First Sergeant (1stSgt).
In February 2022, 1stSgt Harrison accepted orders to II Marine Expeditionary Force Support Battalion (II MSB) where he served as the Marine Air Ground Task Force Command Element Company 1stSgt. In January 2024, 1stSgt Harrison accepted orders to II Marine Expeditionary Force Information Group (II MIG) where he served as the Command Element Company 1stSgt.
In November 2024, 1stSgt Harrison was selected to the rank of Sergeant Major and received orders for December 2024 to Combat Logistics Battalion 24, Combat Logistics Regiment 2. 2d MLG, Camp Lejeune, NC.