Brigadier General McWilliams is a native of Downingtown, PA. He graduated from West Virginia University with a Bachelor of Science Degree in Political Science and was commissioned in 1994 and assigned as an infantry officer. In 1997, he transitioned military occupational specialties and assigned as a logistics officer.

His operational assignments include: rifle platoon commander, weapons platoon commander, and company executive officer, 1stBn, 5th Marines; company commander and battalion operations officer, 2d Landing Support Battalion; II MEF G-4 assistant strategic mobility officer and aide-de-camp for Commanding General, II Marine Expeditionary Force; S-4 Officer, 22d Marine Expeditionary Unit (Special Operations Capable); G-3 Future Operations/Plans Officer and Deputy G-3, 2d Marine Logistics Group; Commanding Officer, Combat Logistics Battalion 8; Assistant Chief of Staff G-3/5, Marine Corps Logistics Command; Commanding Officer, Combat Logistics Regiment 2, 2d Marine Logistics Group; and Deputy Commander, Marine Forces Reserve and Marine Forces South.

His supporting establishment assignments include: Congressional Fellow, serving as a legislative assistant to Representative Norman Sisisky (4th District of Virginia); Interagency Coordinator/Planner and Deputy Division Chief, Chairman’s Exercise Program, The Joint Staff J-7; and Executive Assistant for Deputy Commandant Installations and Logistics, Headquarters Marine Corps.

His military education includes: Infantry Officer Course; Logistics Officers Course; U.S. Army Combined Logistics Officer Advanced Course (Commandants List/CASCOM Award); USMC Command and Staff College (Distinguished Graduate); USMC School of Advanced Warfighting; and The Eisenhower School (formerly ICAF).

Brigadier General McWilliams holds a Master of Business Administration from Boston University; a Master of Military Studies and Master of Operational Studies from Marine Corps University; and a Master of Science in National Resource Strategy from National Defense University.