In 1995, he graduated from the United States Army War College in Carlisle, Pennsylvania.

In 1971, he attended Louisiana State Officer Candidate School, where he was issued a commission as a second lieutenant.

In September 1973, he was awarded his first military command with Detachment 1, 2225th Engineer Company, (LAANG, Jena, Louisiana).

In September 1986, he took command of 527th Engineer Battalion, (LAANG, Bossier City, Louisiana).

General Landreneau worked for the United States Department of Agriculture - Natural Resources Conservation Service for over 30 years and retired as the assistant state conservationist in 1996 before appointment to the adjutant general of the Louisiana National Guard.