Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Clarence Harrison DeMar (June 7, 1888 June 11, 1958) was a U.S. marathoner, winner of seven Boston Marathons, and Bronze medalist at the 1924 Paris Olympics. He was known by the nickname "Mr. DeMarathon." DeMar was born in Madeira, Ohio. The 1910 Boston marathon was DeMar's first; he finished 2nd. Later in 1910 he was advised by a doctor that he had a heart murmur and should stop running within a year or two. The next year at the Boston marathon the doctors on the starting line advised him of his heart murmur and told him that he should drop out if he was fatigued, and that he should not run any more races. Nevertheless, he won in 2:21:39, a course record. DeMar was one of the twelve members of the U.S. marathon team in the 1912 Summer Olympics, where he ran poorly, finishing 12th, complaining that the coaching staff's dictatorial control over the athletes' training had harmed the team's performance.