In 1861, the Tremont House, a six-story brick hotel in Chicago, was raised by 6 feet (1.83 meters) while continuing to operate with customers inside. This unusual feat was part of a larger effort in the 1850s and 1860s to raise Chicago’s streets to accommodate a new sewer system. The city, built at the level of Lake Michigan, could not drain its waters, so it raised its streets instead. Property owners had to either demolish and rebuild or lift their buildings, and many chose the latter when their structures were in good condition. The process of raising buildings involved using hundreds of screw jacks—mechanical devices that lift by turning a screw. The first successful trial of this technique took place in January 1858, when a masonry building was raised by 6 feet 2 inches (about 1.88 meters). By 1860, a block of about 98 meters of façade on Lake Street was lifted by 4 feet 8 inches (about 1.42 meters) using 600 workers and 6,000 jacks over five days. George Pullman, who later became famous for inventing the sleeping car for rail travel, was part of the team that carried out this operation. The Tremont House, located at the corner of Lake Street and Dearborn Street, was raised by 6 feet (1.83 meters) to align with the new street level by the company Ely, Smith & Pullman in 1861. The operation required hundreds of workers and thousands of jacks, with workers operating in covered trenches under the building to limit what customers could see or hear. According to some accounts, an American senator was staying in the hotel without realizing the building was being raised. An often-told story suggests that a customer noticed the entrance steps becoming steeper over time, with windows he had known at eye level later being above his head when he left. Pullman promised to carry out the work without disturbing a customer or breaking a single window. He built his reputation as a building lifter before moving on to his more famous work in transportation. The Chicago Daily Tribune covered the operation on its front page on February 26, 1861. The reported workforce varies across accounts, leading to the use of approximate figures. The spectacle of the operation was so impressive that the artist Edward Mendel created a large lithograph of it, which was later used as a promotional tool.