Boomer saw combat action from 1966 to 1967 in the Republic of Vietnam as the commanding officer, Company H, 2nd Battalion, 4th Marines.

On completion, he was promoted to major in May 1968, and was transferred to Headquarters Marine Corps, Washington, D.C., for duty as the administrative assistant and aide-de-camp to the Deputy Chief of Staff for Plans and Programs.

While serving this tour of duty, he was involved in the defense of Firebase Sarge during the Easter Offensive, North Vietnam's largest assault on the South.

Returning to the mainland US in July 1980, he attended the Naval War College, Newport, Rhode Island, graduating with distinction in June 1981.

He then assumed the duties as the deputy director of the Fourth Marine Corps District, Philadelphia.

During February 1985, Boomer returned to Quantico to assume command of the Marine Security Guard Battalion.

He held this post until 27 May 1988, when he was assigned duty as the commanding general, 4th Marine Division (Reinforced), FMF, New Orleans.

He was promoted to general on 1 September 1992 and assumed his last duty assignment as assistant commandant of the Marine Corps.

He joined Rogers Corporation – an international specialty materials manufacturing company[3] — in 1997 as president and CEO.