Flight O'Hare International Airport departs from Chicago O'Hare International Airport at 15:00 and arrives at Rome Leonardo da Vinci–Fiumicino Airport at 07:20.
The flighttime is about 9h 20m. The distance travelled ("as the bird flies"): 11136 Km. So the average speed is roughly 1193 Km.
There is an 7 hour time difference between Chicago and Rome