[1][2] Dean joined the Missouri Army National Guard’s 175th Military Police Battalion in 1948.

Dean completed the Reserve Officer Training Corps program at the University of Missouri in 1952, and received a Bachelor of Science degree in civil engineering and business.

[4] Commissioned a second lieutenant of Field Artillery, after completing his initial training Dean served in the Korean War.

[5] Dean rejoined the Missouri Army National Guard, and advanced through command and staff assignments of increasing rank and responsibility.

[8][9] Dean was appointed deputy director of the Army National Guard in 1983 and promoted to brigadier general.