The history of the USMC goes back to the very beginning of Reach.
Way back in the first weeks of Reach, Tanker and Grunt had plans for a clan, however not much was done until after the UN ordeal. Grunt and I, after having left the UN, officially started the Marine Corps. For a while the clan was doing great, member count was increasing, and we still had an undefeated record. We had numerous allies and were the most feared clan in the game. So many times assassins attempted to destroy our foundation, and every time we foiled their plans. Then came the "dark times", nothing in Reach but war and fighting, more and more members leaving every day. We were accumulating unwanted and unnecessary enemies. Unable, and unfit, to properly restore the clan Tanker and Grunt disbanded the USMC for roughly five months. After a prolonged conversation, and reading and hearing several statements about how we "were the best", me and Grunt decided we had to keep the Marines up and running... so we brought her back better than ever. So today the USMC is running better than ever. We still are the best, we're undefeated and it will stay that way.