He enlisted in the Marine Corps in February 1971 and underwent recruit training at Marine Corps Depot, San Diego. He received infantry training at Camp Pendleton, followed by training at Sea School, MCRD San Diego.
In December 1971, SgtMaj. Brown reported for a tour of sea duty aboard the aircraft carrier, USS Oriskany. After two lengthy WESTPAC deployments, he reenlisted in 1974 and transferred to the 3rd Marine Division serving 13 months with 1st Battalion, 9th Marines and 12 months with 3rd Battalion, 4th Marines.
In 1976, SgtMaj. Brown transferred to Camp H. M. Smith, Hawaii, where he served as a primary marksmanship instructor at the rifle range. In 1979, he received orders to Drill Instructor Duty at MCRD, San Diego. Assigned to India Company, 3rd Recruit Training Battalion, he served 18 months as a drill instructor and senior drill instructor. In November 1980, he was meritoriously promoted to gunnery sergeant and assigned duties as an instructor at Drill Instructor School.
In April 1983, SgtMaj. Brown transferred to 2nd Battalion, 3rd Marines at Kaneohe Bay, Hawaii. He served in Weapons Company as the operations chief and in Gold Company as the company gunnery sergeant. In May 1985, he was reassigned to the Brigade NCO School as the SNCOIC until his selection to first sergeant. In July 1986, he was reassigned to Company "A," 3rd Reconnaissance Battalion as the company first sergeant.
Sergeant Major Brown transferred in April 1987 to Marine Barracks, Subic Bay, Philippines, as first sergeant of Company "C" for one year and Company "B" for two years. In July 1990, he transferred to the School of Infantry, Marine Corps Base Camp Pendleton, to serve as the sergeant major of H&S Battalion, School of Infantry. In March 1991, he was reassigned as the sergeant major of the Marine Combat Training Battalion. He was promoted to his present rank in June 1991.
Sergeant Major Brown was reassigned in February 1993 to serve as the sergeant major of the Marine Corps Tactical Systems Support Activity, MCB Camp Pendleton. In March 1994, he was assigned as the sergeant major of Headquarters and Headquarters Squadron, Marine Corps Air Station El Toro. He posted as sergeant major of the 31st MEU on June 11, 1996.
Sergeant Major Brown's personal decorations include the Meritorious Service Medal, the Navy Commendation Medal, and the Navy Achievement Medal with gold star in lieu of a second award.