Built in 1982, by Jeffboat Incorporated of Jeffersonville, Indiana as the Exxon Chicago for the Exxon Shipping Company of Wilmington, Delaware.
In 1993, in the wake of the Exxon Valdez incident. The Exxon Shipping Company was rebranded as the SeaRiver Maritime Company of Houston, Texas. Where the tug was renamed as the S/R Chicago.
In 1999, the Exxon Oil Company merged with the Mobil Oil Corporation to form the ExxonMobil Corporation of Irving, Texas. The SeaRiver Maritime Company continued to operate as a subsidy of the ExxonMobil Corporation. And, the tug retained her name.
In 2003, she was acquired by the Kirby Corporation of Channelview, Texas. Where the tug was renamed as the City of Chicago.
Powered by two, GM 16-645E6 diesel engines. With Falk reduction gears, at a ratio of 3.958:1. She is a twin screw, square bow, push boat, rated at 4,200 horsepower.