Roswell Winans was born December 9, 1887, in Brookville, Indiana as the son of William C. Winans and Mary Davenport. He was youngest of four children and following the high school, Winans worked for two years in Alaska, before joining the United States Army at Jonesboro, Arkansas in February 1906. After leaving the army, Winans joined United States Marine Corps on October 10, 1912 as Sergeant and was attached to the Marine Barracks at Mare Island Navy Yard, California. He later participated in the occupation of Veracruz with 1st Marine Brigade in April 1914 and later received Marine Corps Good Conduct Medal for his enlisted service.