This historic tug was built in 1919 by the Whitney Brothers of Superior as the Humaconna for the U.S. Shipping Board. In 1923 the steam-powered tug was sold to Merrill & Ring Lumber. She was then sold to the Western Pacific Railroad in 1940, and spent 19 years in their fleet. In 1952, the Humaconna was repowered with a Cleveland 16-258S engine to replace her triple expansion steam powerplant. In 1959 she was sold to John H. Caughran, then Lewis L. Vehland in 1960, and again to Any Ocean Towing Service in 1961. Nicholson Transit of Detroit, MI acquired the tug in 1962, and brought her back onto the Great Lakes for the the first time since her construction. William W. Stender of Bay City, Michigan purchased the Humaconna in 1969, and continued to operate her until 1977. Capt. Gregory Busch bought the tired old tug in 1977, and completely rebuilt it, including new steel, brand-new cabins, and new engines. The Humaconna was renamed Gregory J. Busch in 1977, and entered service as the first tug of Busch Marine. A Hydraconn coupler system was later added to pair her with the deck barge STC 2004.

Gregory J. Busch has seen limited service since the late 2010s and currently spends much of her time docked in Carrollton, Michigan on the Saginaw River.