Chicago

41.8781°N, 87.6298°W.

S. city, founded 1833 at the mouth of the Chicago River where it enters Lake Michigan. The city was built on a swamp; in 1856 engineer Ellis Chesbrough and his crew physically raised the entire downtown by jacking up buildings up to two metres while occupants continued to live in them, installing modern sewers underneath. The 1871 fire destroyed 1,160 acres of the city; reconstruction within 22 years gave Chicago the world's first steel-frame skyscraper (Home Insurance Building, 1885, William Le Baron Jenney). The Chicago River was reversed in 1900 by the construction of the Sanitary and Ship Canal — the river now flows away from Lake Michigan rather than into it, dumping the city's wastewater toward the Mississippi instead. Willis Tower (1973, 442 m) was the world's tallest building for 25 years.

Chicago raised itself out of a swamp, then reversed the river that flowed past it, then invented the skyscraper — within forty years.