Corporal Gallivan is a college graduate of Indian River State College with a 4-year degree in Criminal Justice.
After college, CPL Gallivan joined the United States Marine Corps where he served four years active duty as a Fire Support Man and as Joint Fires Observer for 1st Battalion 12th Marines.
Before joining the Hargrave community, he worked at Riverside Military Academy for two years as a TAC Officer for Band and Golf Company.