The E-class submarines were a class of two United States Navy submarines, built by the Fore River Shipbuilding Company of Quincy, Massachusetts, under a subcontract from the Electric Boat Company. They were used as coastal and harbor defense submarines prior to World War I. When hostilities broke out, the E class were mostly used as training boats; however, E-1 operated on war patrols based in the Azores. During this time, the need for an improved permanent bridge structure was discovered; the temporary piping-and-canvas bridges were inadequate in the North Atlantic.

USS E-2 (SS-25) was an E-class submarine of the United States Navy. Originally named Sturgeon, the boat was launched on 15 June 1911 by the Fore River Shipyard, Quincy, Massachusetts; sponsored by Ms. Margaret Nelson Little; renamed E-2 on 17 November 1911; and commissioned on 14 February 1912d.