Tom Hanks is driving his car over a bridge in downtown Chicago in 1931. In the background is the elevated train structure. An aluminum bodied train passes on the trestel in the background. This aluminum bodied train is of 1980's contruction. In the 1930's the train cars were of wood construction and painted brown. I remember riding them for they were still in service in the 1950's.
Jude Law's character, Maguire, was based on Arthur Fellig, who photographed bodies at crime and fire scenes, then sold them to the tabloids. The photos shown in Maguire's apt are real crime scene photos and some were taken by Fellig himself.