This practice was not unique to the City of Chicago.
The city of Naples was rebuilt at great expense after the a terrible cholera epidemic in 1884 carried off a large number of victims. In response the government funded major effort to raise the city's streets as proscribed by the then current Miasmatic Theory of Disease. The thinking was along of the lines of low lying 'bad air' caused illnesses and thus the raising of the city's infrastructure would improve the general health.
The city of Naples was rebuilt at great expense after the a terrible cholera epidemic in 1884 carried off a large number of victims. In response the government funded major effort to raise the city's streets as proscribed by the then current Miasmatic Theory of Disease. The thinking was along of the lines of low lying 'bad air' caused illnesses and thus the raising of the city's infrastructure would improve the general health.
Details: https://en.wikipedia.org/wiki/Miasma_theory_of_disease