The solution was to raise the city. Wooden homes were often relocated, sold and moved out of the new city center so that new masonry buildings could be built on new foundations at the new grade. But the larger buildings were raised. Teams of hundreds of men with thousands of jacks dug out under the stone and iron buildings and jacked them up to a new level. The streets were then filled in to the new grade.
By 1860, confidence was sufficiently high that a consortium of no fewer than six engineers; including James Brown, James Hollingsworth and George Pullman took on one of the most impressive locations in the city and hoisted it up complete and in one go. They lifted half a city block on Lake Street, between Clark Street and LaSalle Street; a solid masonry row of shops, offices, printer shops, etc., 320 feet long, comprising brick and stone buildings, some four stories high, some five, having a footprint taking up almost one acre of space, and an estimated all in weight including hanging sidewalks of thirty five thousand tons.It wasn't impossible because they believed they could.
Businesses operating out of these premises were not closed down for the lifting; as the buildings were being raised, people came, went, shopped and worked in them as if nothing out of the ordinary were happening. In five days the entire assembly was elevated 4 feet 8 inches clear in the air 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.