John Mark Clapp ’74

Mark died Oct. 6, 2025, at Walter Reed National Military Hospital in Maryland of leukemia. 

Born Sept. 17, 1952, in Jos, Nigeria, where his parents were missionaries, Mark grew up in Philadelphia and graduated from Abraham Lincoln High School. At Princeton, he majored in biology and competed in rugby, lightweight football, and gymnastics. He lived in third entry Hamilton and sixth entry Patton and formed lifelong friendships with his roommates, who always remember Mark for driving to Kentucky over Christmas break to fill in for the Princeton cheerleaders at the University of Kentucky Invitational basketball tournament. 

Through the Platoon Leaders Class program, Mark began his lifelong commitment to the Marine Corps. He retired as a colonel after three tours of service and multiple honors. In civilian life, he built a career in defense acquisition and consulting while continuing to support Marines. 

Kind, loyal, and deeply patriotic, Mark was devoted to his country, friends, and family. He is survived by his wife, Malka “Mally;” daughter, Melissa; two grandchildren; and his siblings. Mark is buried at Arlington National Cemetery. The class extends its deepest condolences to the Clapp family and our gratitude to Mark for his service.