Title: Baltimore Sabotage Cell
Subjects: World war, 1914-1918, naval operations, submarine, Espionage, german, World war, 1914-1918, secret service, World war, 1914-1918, germany, World war, 1914-1918, united states, Sabotage, World War, 1914-1918, United States Bureau of Investigation, Baltimore Sabotage Cell, United States, Submarine, Secret service, German Espionage, Deutschland (Submarine), Naval operations, German Naval operations, History