After operation by WSA's agent Waterman Steamship Company June 1945 – November 1946 and being placed in reserve the ship was transferred to the U.S. Army and renamed USAT Sgt.

Joseph E. Muller was laid down under U.S. Maritime Commission contract (MC hull 2485) as Check Knot on 30 December 1944 by the Southeastern Shipbuilding Corporation, Savannah, Georgia and launched on 17 February 1945 sponsored by Mrs. D. R.

[1] Title was transferred to the U.S. War Department on 30 June 1948 for operation by the Army Transportation Service with the ship being renamed Sgt.

[2][4] Through the Korean War, she continued to shuttle passengers and cargo—primarily to Japan and Korea, but with an occasional run to Okinawa, Taiwan, and the Philippines.

Initially slated for Arctic resupply missions, she was transferred temporarily and in ready status to the Maritime Administration's National Defense Reserve Fleet (NDRF), Hudson River berthing area, on 7 December 1956, and, in September 1957, was declared surplus to the needs of the Navy.

Joseph E. Muller was designated for activation, conversion to a research support ship, a cover for signals intelligence operations, and redelivery to the Navy on 20 September 1962.