Sergeant Major Shane Henson enlisted in the Marine Corps in January 1993. Upon completion of recruit training and the School of Infantry he was assigned the MOS of 0351, Anti-Tank Assaultman..
Upon graduation from Infantry Training Battalion, he was assigned to Weapons Company, 1st Battalion 4th Marines as a Dragon Gunner and subsequently deployed with both the 15th and 13th Marine Expeditionary Units.
In March 1998, Corporal Henson was transferred to serve as an Infantry Instructor at 1st Marine Division Schools. In August 1998, Sergeant Henson was transferred to Weapons Company, 2nd Battalion, 23rd Marines, 4th Marine Division for service as the assistant training chief.
In June 2002, Staff Sergeant Henson was assigned to the School of Infantry as a Marine Combat Instructor where he held billets as a senior combat instructor, Company Gunnery Sergeant, and an instructor of the Marine Combat Instructors Course. In January, 2005 Gunnery Sergeant was reassigned as an instructor of Infantry Squad Leaders Course.
In October 2005, Gunnery Sergeant Henson was transferred to 1st Battalion 7th Marines, 1st Marine Division where he served as the Weapons Company Operation Chief and Alpha Company Gunnery Sergeant serving two tours of duty in the Al Anbar Province in support of Operation Iraqi Freedom.
In May of 2008, Gunnery Sergeant Henson was frocked to the rank of First Sergeant and assumed his duties as the Marine Corps Logistics Command Headquarters Company 1st Sergeant.
In June of 2011, First Sergeant Henson was reassigned to 5th Battalion, 10th Marines, where he served as the Golf Battery 2D Battalion, 12th Marines Battery First Sergeant, where he deployed to Okinawa, Japan in support of the Unit Deployment Program.
On 5 June, upon deactivation of 5th Battalion, 10th Marines, First Sergeant Henson was reassigned to 2nd Combat Engineer Battalion where he served as the Headquarters and Service Company First Sergeant and deployed to Helmand Province, Afghanistan in support of Operation Enduring Freedom.
In December of 2013, Sergeant Major Henson was frocked to his current rank and assigned as the Battalion Sergeant Major of 1stBattalion, 10th Marines.
In June of 2015, Sergeant Major Henson assumed his duties as the Inspector-Instructor Sergeant Major of 2nd Battalion 23rd Marines.