Harry Addison March (December 11, 1875 – June 10, 1940) was an early football historian and promoter, as well as a medical doctor. He also helped organize the National Football League and well as the second American Football League. March is also credited with convincing Tim Mara to purchase an NFL franchise for New York City, which is still in existence today as the New York Giants. He wrote one of the first books on the history of the professional game: Pro Football: Its Ups and Downs in 1934. Dr. March is known as the "Father of Professional Football."