Businesses operating in these premises were not closed down during the operation

It is humor but I was intrigued by the historical claim.  

Did Chicago really jack itself up to improve drainage in the 1850s?  Having read accounts of the 1893 World's Fair, it certainly seems conceivable but I had never heard of it before.

First stop is Wikipedia and sure enough:

During the 1850s and 1860s, engineers carried out a piecemeal raising of the level of central Chicago. Streets, sidewalks, and buildings were physically raised on jackscrews. The work was funded by private property owners and public funds.

During the 19th century, the elevation of the Chicago area was little higher than the shoreline of Lake Michigan, so for many years, there was little or no naturally occurring drainage from the city surface. The lack of drainage caused unpleasant living conditions, and standing water harbored pathogens that caused numerous epidemics including typhoid fever and dysentery, which blighted Chicago six years in a row, culminating in the 1854 outbreak of cholera that killed six percent of the city’s population.

The crisis forced the city's engineers and aldermen to take the drainage problem seriously and after many heated discussions—and following at least one false start—a solution eventually materialized. In 1856, engineer Ellis S. Chesbrough drafted a plan for the installation of a citywide sewerage system and submitted it to the Common Council, which adopted the plan. Workers then laid drains, covered and refinished roads and sidewalks with several feet of soil, and raised most buildings to the new grade. 

In January 1858, the first masonry building in Chicago to be thus raised—a four-story, 70-foot (21 m) long, 750-ton (680 metric tons) brick structure situated at the north-east corner of Randolph Street and Dearborn Street—was lifted on two hundred jackscrews to its new grade, which was 6 feet 2 inches (1.88 m) higher than the old one, “without the slightest injury to the building.”[8] It was the first of more than fifty comparably large masonry buildings to be raised that year.[9] The contractor was an engineer from Boston, James Brown, who went on to partner with Chicago engineer James Hollingsworth; Brown and Hollingsworth became the first and, it seems, the busiest building raising partnership in the city. By the year-end, they were lifting brick buildings more than 100 feet (30 m) long, and the following spring they took the contract to raise a brick block of more than twice that length.

In 1860 a consortium of no fewer than six engineers—including Brown, Hollingsworth and George Pullman—co-managed a project to raise half a city block on Lake Street, between Clark Street and LaSalle Street complete and in one go. This was a solid masonry row of shops, offices, printeries, etc., 320 feet (98 m) long, comprising brick and stone buildings, some four stories high, some five, having a footprint taking up almost one acre (4,000 m2) of space, and an estimated all in weight including hanging sidewalks of thirty-five thousand tons. Businesses operating in these premises were not closed down during the operation; as the buildings were being raised, people came, went, shopped and worked in them as they would ordinarily do. In five days the entire assembly was elevated 4 feet 8 inches (1.42 m) by a team consisting of six hundred men using six thousand jackscrews, ready for new foundation walls to be built underneath. The spectacle drew crowds of thousands, who were on the final day permitted to walk at the old ground level, among the jacks.

Amazing.  A people of vision and energy then.  Shrunk now to vestiges.