leo andrew walton was born on october 7, 1890, in salem, oregon. he attended united states military academy at west point, new york, and graduated in 1915 as a part of "the class the stars fell on" (because 59 members of this class became general officers). he was commissioned a second lieutenant of cavalry on june 12, 1915, and subsequently participated in the pancho villa expedition in mexico under general john j. pershing.