Chicago’s population was 350 people in 1835 and grew to over 60,000 by mid-century. This tremendous growth presented many plumbing problems, which were solved in 1869 when the city unveiled a new engineering feat that made newspaper headlines around the world.

Together, architects and plumbers created a twin-tunnel sanitary water system, which extended two miles out into Lake Michigan. Offshore, the clean water entered an underwater shaft leading to a tunnel below the lakebed.