She was laid down as an Oregon City-class heavy cruiser (CA–125), on 31 August 1944 by the Fore River Yard, Bethlehem Steel Corp., Quincy, Massachusetts.

Work suspended between 11 August 1945 and 1 July 1948; she was converted to a command cruiser under project SCB 13 and launched as CLC–1, on 27 January 1951; sponsored by Mrs. Edmond J. Lampron; and commissioned as CLC–1, on 7 March 1953.

Her cruises ranged from Canadian to Panamanian waters as she extensively tested and evaluated new communications equipment and played host to visiting national and international dignitaries, including Presidents John F. Kennedy and Lyndon B. Johnson.

[1] According to a Washington Post article on 29 July 2006, Northampton was part of the U.S. government's plan for Continuity of Operations and reported to be a "floating White House" to which the President could be evacuated in the event of nuclear attack.

As such she was designated as the National Emergency Command Post Afloat (NECPA); Northampton was one of two ships to serve in the role, with the other being the aircraft carrier USS Wright.