The raising of Chicago in 1855: The feat that lifted an entire city on mechanical jacks without stopping trade

In the mid-19th century, Chicago was literally drowning in its own mud. Built almost level with the waters of Lake Michigan on swampy land, the city lacked a natural slope to drain wastewater. Streets were quagmires where carriages got stuck, and outbreaks of cholera and typhoid fever threatened to wipe out the population. In 1855, engineer Ellis S. Chesbrough proposed a solution as radical as it was audacious: build a sewer network above the streets and raise the entire city between 1.2 and 4.2 meters.

To accomplish this without demolishing existing buildings, engineers like George Pullman devised a monumental lifting system using thousands of mechanical jackscrews installed under foundations:

• The Tremont House hotel: In 1861, this luxurious six-story brick building weighing over 10,000 tons was raised using 5,000 jacks operated by 500 men working in perfect synchrony. Guests continued sleeping, dining, and drinking at the bar without spilling a single glass.
• Entire city blocks: Entire commercial blocks of half a hectare, made of stone and brick stores, were lifted while shops kept their doors open and customers crossed via temporary footbridges.

Once the new height was reached, masons built permanent foundation walls, and the streets were backfilled with soil and rubble. This astonishing feat of civil engineering not only saved Chicago from epidemics, but also laid the mechanical and logistical foundations that made its rebuilding possible after the Great Fire of 1871.