Awarded to service members performing either one year of consecutive duty between December 7, 1941 to March 2, 1946 within the continental borders of the United States, or performing 30 days consecutive or 60 non-consecutive days of duty outside the borders of the United States but within the American Theater of Operations. The American Theater was defined as the entirety of the United States to include most of the Atlantic Ocean, a portion of Alaska, and a small portion of the Pacific bordering California and Baja California. Service stars were authorized to any service member who was engaged in actual combat with Axis forces within the American theater. This primarily applied to those members of the military which had engaged in anti-U-Boat patrols in the Atlantic.