The Great Chicago Fire
The most well-known tragedy during Chicago's first hundredy years is the Great Chicago Fire of 1871. Starting on October 9, a few blocks left of the south branch of the Chicago River, the fire burned for several days, engulfing the sawdust filled city and its citizens. By the time the fire had burnt out, 300 Chicagoans had perished and 100,000 people, a third of the city's population, had been left homeless.
While the city was decimated for decades to come, Chicago rebranded itself in time to secure the bid for the 1893 World' Columbian Exhibition by overselling how quickly the city had rebuilt itself. Even though this was largely exaggerated, Chicago did eventually rebuild itself, fairly earning the nickname "the Second City" and getting to a point where they could commemorate the tragedy. The disaster is now marked by the second star on Chicago's city flag.