A participant in the 38th Marine Corps Marathon gives a thumbs up while passing spectators in Washinton Oct. 27, 2013. The MCM is currently the fifth largest marathon in the United States and the ninth largest in the world. The People's Marathon is composed of runners from all over the U.S. and more than 50 countries. (U. S. Marine Corps photo by Lance Cpl. Dylan Bowyer/Released) - A participant in the 38th Marine Corps Marathon gives a thumbs up while passing spectators in Washinton Oct. 27, 2013. The MCM is currently the fifth largest marathon in the United States and the ninth largest in the world. The People's Marathon is composed of runners from all over the U.S. and more than 50 countries. (U. S. Marine Corps photo by Lance Cpl. Dylan Bowyer/Released)