In January 1858, the Tremont House — the most fashionable hotel in Chicago, a six-story brick building covering most of a city block at the corner of Lake and Dearborn Streets, with 250 guest rooms and 22,000 square feet of public space — was lifted off its foundations and raised six feet into the air by five thousand jackscrews, each cranked simultaneously by a crew of one man, over a period of about four days. The hotel continued operating during the lift. Guests stayed in their rooms. The kitchens served meals. The bar continued to pour drinks. Most guests, by the contemporary newspaper accounts, did not realize the building was being raised until they walked outside and discovered that the front steps had become a substantial flight up from the new street level.
The Tremont was not unique. Over the course of the late 1850s and early 1860s, the entire central business district of Chicago — hundreds of buildings, including hotels, office blocks, banks, courthouses, churches, residential streets, sidewalks, gas mains, water pipes, and several whole stretches of pavement — was raised, building by building, by between four and fourteen feet above its original ground level. The work was done block by block over fifteen years. Most buildings continued to operate throughout. The cost was paid by the property owners themselves, under a city ordinance that required the raising. The total project was, by reasonable measure, the largest building-lifting operation in American history.
Chicago raised itself because it had no choice. The city had been built on flat lakeside land that drained, or rather did not drain, into Lake Michigan at almost no gradient. The streets were perpetual mud. Sewage from the rapidly growing population (60,000 in 1850, 110,000 in 1860, 300,000 by 1870) was collecting in stagnant pools across the city, with predictable epidemiological consequences. The cholera epidemics of 1849 and 1854 had each killed about five percent of the city’s population. The typhoid that followed was killing comparable numbers every summer. The municipal government had to install a sewer system, and the only way to install a sewer system that drained anywhere was to put the sewers above the natural ground level — and therefore to put the buildings above the sewers.
The engineer who designed the system was a young Boston-trained civil engineer named Ellis Chesbrough. The contractor who became famous for the raising work was, for a few years before he made his fortune in railway sleeping cars, George M. Pullman.
How Pullman did it
The technique was simple in principle and complicated in execution. A building scheduled for raising would first be carefully surveyed. The intended new elevation would be marked. Hundreds or thousands of jackscrews — heavy iron mechanical screws, each capable of lifting between half a ton and several tons — would be installed in the basement under the building’s load-bearing walls and footings. The screws were placed in a grid pattern such that each section of the building’s weight was distributed across multiple screws.
Each screw was assigned a workman with a long iron handle. On the chief engineer’s signal, all the workmen would turn their handles together, one quarter-turn at a time, raising the building by a fraction of an inch with each coordinated turn. The work proceeded in steps of perhaps half an inch per round, with the entire team turning together. Between rounds, the foreman would walk the perimeter of the building checking for cracks or distress and would adjust individual screws to compensate for differential settling. Above the screws, men with bricks and timber would build up the new permanent foundation course beneath the building as it rose. Below the screws, men with shovels would dig out the old basement to lower it relative to the building’s new position.
A typical brick building of five stories could be raised one foot per day. The Tremont House was raised at slightly faster than that — about eighteen inches per day, by some accounts — because the contract specified a five-day completion. The hotel’s guests felt no perceptible motion. The building rose at a rate of roughly a tenth of an inch per minute, perfectly synchronized, all five thousand screws turning together. The only visible sign during operation was that the windows of the upper floors gradually crept upward against the sky.
Once a building was at its new height, a new permanent foundation course was completed beneath it, the screws were removed and either returned to inventory or sold to the next contract, and the building was lowered back onto the new foundation. The space beneath the original ground floor — now several feet above street level — was either filled in or, more usefully, converted into new basement space. Many Chicago buildings of the late nineteenth century have basement levels that were originally ground floors before the raising.
The work for individual buildings was paid for by the owners. The cost of the Tremont House raising, including the basement excavation and new foundation, was approximately $45,000 — an enormous sum, paid by the Couch family who owned the hotel, equivalent to several million dollars in modern terms. Smaller commercial buildings cost between $3,000 and $10,000 to raise. Wood-frame residential buildings could often be raised, in many cases by lifting the entire structure off its old foundation and onto wagons, and physically rolling them to new locations several blocks away. Several thousand wood buildings were relocated during the raising decades, sometimes across multiple property lines, in what amounted to one of the most fluid urban-planning environments of the nineteenth century.
George Pullman ran the raising of several of the largest commercial buildings, including the Marshall Field’s department store block on State Street. He had been a Buffalo cabinet-maker who had moved to Chicago in 1855 specifically to enter the raising trade, having learned the basic techniques on smaller Erie Canal-area projects. The Chicago raising made him famous, well-connected, and rich. By 1864 he had used the proceeds to found the Pullman Palace Car Company, which would within a decade become the largest manufacturer of railway sleeping cars in the world. The technique he had used to lift hotels became, in mechanical translation, the technique he used to lift entire railway cars during assembly.
The thing the raising was for
The sewer system that the raising made possible was designed by Ellis Chesbrough between 1855 and 1858. It consisted of brick-vaulted intercepting sewers running beneath the new elevated streets, draining by gravity into the south branch of the Chicago River, and from there into Lake Michigan. The drinking water intake was at the same time moved further out into the lake by means of a two-mile-long intake tunnel completed in 1867 — the longest underwater tunnel constructed anywhere in the world up to that date, beneath a lake whose bed was unstable and whose surface was frequently storm-tossed.
The combination of the raised streets, the brick sewers, and the deep-water intake substantially reduced cholera and typhoid mortality in Chicago by the mid-1860s. The improvement was not total. The Chicago River, by then carrying the city’s complete sewage output, was contaminating the near-shore water of Lake Michigan where the city’s older shallow intakes still drew water. By the 1870s the river had become so polluted that the city’s eventual solution was to reverse its flow — to dig a canal that made the Chicago River flow inland, away from Lake Michigan, and ultimately into the Mississippi watershed. That project, completed in 1900, made Chicago the only major city in the world that had successfully reversed the natural flow of a river to push its sewage away from its drinking water. The downstream effects on St. Louis, which now received Chicago’s sewage by way of the Illinois and Mississippi Rivers, were the subject of an interstate lawsuit that the United States Supreme Court eventually decided in Chicago’s favor.
What was left behind
Some of the buildings raised in the 1850s and 1860s are still standing. The Tremont House itself was destroyed in the Great Chicago Fire of October 1871, along with most of the central business district. A new Tremont House was built on the same site after the fire, raised to the post-1870 elevation, and operated until 1972. The current building on the corner of Lake and Dearborn is a 1980s office tower. There is no plaque.
What remains visible of the raising today is mostly in the basements of the few pre-1871 buildings that survived the fire. The Couch tomb on the southern edge of Lincoln Park is the only surviving structure of pre-fire Chicago that is still at its original ground level — it was a small stone mausoleum built in 1857 just before the lakefront cemetery on that site was closed, and was left in place when the cemetery was relocated to make room for the park. Visitors to Lincoln Park can stand next to the tomb and look up to see that the surrounding park sits roughly four feet above the tomb’s base. The Couch family never moved the tomb. It is, as far as anyone has ever determined, the only piece of central Chicago that the raising did not lift.
The Couches themselves were the family that owned the Tremont House. They had been the ones who paid Pullman to raise their hotel by six feet in January 1858. The mausoleum’s stubborn refusal to follow the rest of the city upward is sometimes read, by Chicago historians of an ironic disposition, as the family’s small joke at municipal expense.