The yard was on League Island in the Delaware River in Philadelphia, Pennsylvania, and was originally established by the United States Navy in 1801.
The Naval Aircraft Factory was established there in 1917.
Its greatest period came in World War II, when the yard employed 40,000 persons in the construction of 53 ships and the repair of 574.
After the war, the workforce dropped to 12,000, and in the 1960s new ships began to be contracted out to private companies. The last new ship constructed was the command ship USS Blue Ridge, in 1970.
The yard's closure was originally recommended in 1991 by the Defense Base Closure and Realignment Commission, as a recognition of reduced needs due to the end of the Cold War, but unsurprisingly, the potential loss of some 7,000 jobs resulted in the involvement of Senator Arlen Specter.
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