High Quality Content by WIKIPEDIA articles! USS Philadelphia (SSN-690), a Los Angeles-class attack submarine, was the sixth ship of the United States Navy to be named for Philadelphia, Pennsylvania. The contract to build her was awarded to the Electric Boat Division of General Dynamics Corporation in Groton, Connecticut on 8 January 1971 and her keel was laid down on 12 August 1972. She was launched on 19 October 1974 sponsored by Mrs. Hugh Scott, and commissioned on 25 June 1977, with Commander Robert B. Osborne in command.