Built in 1953, by RTC Shipbuilding Incorporated of Camden, New Jersey (hull #212) as the Liberty for the Central Railroad Company of New Jersey of New York, New York.
The tug was constructed with with lower wheelhouse, and stack for service on the Harlem River in New York city.
In 1956, the tug was acquired by the Baltimore and Ohio Railroad Company of Baltimore, Maryland. Where she was renamed as the J.W. Phipps, Jr.
In 1965, she was acquired by the Chesapeake & Ohio Railway of Hampton Roads, Virginia. Where the tug was renamed as the M.I. Dunn.
In 1973, the Chesapeake and Ohio Railway Company was absorbed into the Chessie System of Baltimore, Maryland. Where the tug retained her name.
In 1984, the tug was acquired by the DonJon Marine Company Incorporated of Hillside, New Jersey. Where she was renamed as the James M. Witte.
In 1992, she was chartered to Hepburn Marine Towing Incorporated of New York, New York. Where tug tug retained her name.
In 1994, the tug was returned to the DonJon Marine Company Incorporated of Hillside, New Jersey. Where she retained her name.
In 1994, she was acquired by Krause Marine Towing Corporation of Perry Hall, Maryland. Where the tug was renamed as the Theresa S. Krause
In 2023, the tug was phased out of active service. And was "laid up" at Baltimore, Maryland.
Originally powered by a single, Fairbanks-Morse 10-38D 8 1/8 diesel engine, for a rated 1,600 horsepower. In 2008, the tug was re powered with a single EMD 16-645 diesel engine. With a Reintjes reduction gear, at ratio of 4.5:1. She was a single screw tug, rated at 3,000 horsepower. In 2008, a kort nozzle and flaking rudder were added as well.