Editing In Old Chicago (section)

==Historical accuracy==
Despite crediting the [[Chicago History Museum|Chicago Historical Society]] for assistance with historical research, much of the film is fictionalized. The area known as "the Patch" did exist as a predominantly Irish neighbourhood, and was associated with crime, as portrayed in the film.<ref>Herbert Asbury, ''The gangs of Chicago: an informal history of the Chicago underworld'', Random House, 2003, p.xvii.</ref> In the years before the film was made it had been supplanted by [[the Levee]], an area renowned for its corrupt politicians, known as the [[Gray Wolves (Chicago)|Gray Wolves]], whose deeds resemble those of the characters in the film.<ref>[[William Targ|Targ, William]], ''Indecent pleasures: the life and colorful times of William Targ'', Macmillan, 1975, p.17.</ref>

The portrayal of the O'Leary family is largely fictitious down to the names of the characters. Mrs. O'Leary's name was Catherine, not Molly. The O'Learys had two children, one son and one daughter. In the movie there are three sons. Her only son was named [[James Patrick O'Leary]]. The daughter was named Anna. Their father Patrick O'Leary did not die in 1854 as a result of an accident involving his horses. He died in 1894.<ref name="graveyard">{{cite web| publisher=Graveyards of Chicago| title=Patrick and Catherine O'Leary| url=http://graveyards.com/IL/Cook/mtolivet/oleary.html| access-date=2011-09-23}}</ref> Mrs. O'Leary did not run her own "French Laundry" out of their house.

The Mayor of Chicago in 1871 was [[Roswell B. Mason]], not an O'Leary son. However, Mason was elected on a reform ticket like the fictional Jack and took similar measures to deal with the fire. Mrs. O'Leary's son James Patrick did achieve success as a gambler and saloon owner comparable to that of Dion in the film.