Martin Francis Scanlon was born in Scranton, Pennsylvania, on 11 August 1889. He attended the University of Pennsylvania from 1908 to 1909, and Cornell University from 1910 to 1911, before being commissioned in the United States Army as a second lieutenant in the Infantry on 24 April 1912. He initially served with the 7th Infantry Regiment, but transferred to the 19th Infantry Regiment. This regiment patrolled the border with Mexico from Fort Crockett, Texas. He participated in the United States occupation of Veracruz from May to October 1914, when the 19th Infantry returned to Galveston, Texas.