Constructed to provide a safe, potable water supply for the citizens of Chicago, Ellis Chesbrough's Chicago Water Supply System was the first major system to utilize offshore intake systems. The system includes the landmark Chicago Water Tower and the Chicago Avenue Pumping Station. Its subaqueous tunnel was a pioneering effort in American civil engineering.
The Chicago, Burlington, & Quincy Railroad was the first railroad to link Chicago and the Mississippi River, in the 1850s. This forty-stall roundhouse, large even for its time, became a major center for railroad activity for the CB&Q. It served as a repair and construction facility from which more locomotives and cars than any other CB&Q installation were built. Steam engines, passenger cars, freight cars, precision parts, tools, and machines were designed and built, beginning about 1858.