The Battle of the Atlantic was the longest continuous military campaign of World War II, spanning from 1939 to 1945. This vital struggle determined whether Britain and the Commonwealth could maintain their lifelines to North America and later to the Soviet Union. This course will explore the German U-boat war against Allied shipping and naval forces during the war. It will discuss the various submarine types used by the Kriegsmarine and the equipment and technology used by the Allies to counter this threat. We will discuss the various phases of the Battle of the Atlantic, with a focus on the American forces, including the comparative successes and failures during each phase. The course will also explore why the Allies were eventually more successful in the Battle of the Atlantic compared to the Japanese anti-submarine effort in the Pacific Theater of Operations.