The Great Chicago Fire is a conflagration that burns from Sunday, October 8, to early Tuesday, October 10, 1871, killing hundreds and destroying about 3.3 square miles (9 km2) in Chicago, Illinois.
Though the fire is one of the largest U.S. disasters of the 19th century, the rebuilding that begins helps develop Chicago as one of the most populous and economically important American cities.On the flag of Chicago, the second star commemorates the fire.
The exact cause is never determined.
The popular account dreamed up by a reporter, attributing it to Mrs. Catherine O'Leary and her cow, survives his confession of fiction in 1893.
