Marine Forces Reserve | 17,468 followers on LinkedIn. We augment, support, and reinforce the Total Force Marine Corps | Marine Forces Reserve is the headquarters command for approximately 100,000 Reserve Marines and 160 Reserve Training Centers located throughout forty-seven of the United States, Washington D.C., and Puerto Rico. The United States Marine Corps Reserve was established when Congress passed the Naval Appropriations Act of Aug. 29, 1916 and is responsible for providing trained units and qualified individuals to be mobilized for active duty in time of war, national emergency, or contingency operations. Marine Forces Reserve also provides personnel and operational tempo relief for active component forces in peacetime.