In March 1972, he reported to Marine Corps Recruit Depot San Diego, where he served as a series commander and Director of the Sea School until July 1975.

After graduation from the Marine Corps Command and Staff College in June 1985, he was assigned to the Air-Ground Exchange Program with MAG-26 where he served as the S-3A and S-3.

Upon completion of his tour with the Marine Expeditionary Unit, in March 1995, he assumed duties as the Military Assistant to the Secretary of the Navy.

Upon arrival at USCENTCOM in August 2001, he assumed duties as Director, Resources and Assessment, J8, United States Central Command MacDill Air Force Base, Florida.

[1] In October 2002, Blackman was assigned as the Chief of Staff for Coalition Forces Land Component Command during Operation Iraqi Freedom.