The American Defense Service Medal is a United States Armed Forces military award established by President Franklin D. Roosevelt on June 28, 1941 (Executive Order 8808). The medal recognizes military service members who served on active duty between the dates of September 8, 1939 and December 7, 1941. There is a similar medal, called the American Campaign Medal, that was established in 1942 for operations during World War II. 
 
Members of the United States Army and the Army Reserve and Army National Guard could receive this medal for any length of service provided that they were on orders to active duty for at least twelve months or longer and had passed their initial physical examinations. The Navy excluded reservists that had been on duty for less than ten dates.