Flight O'Hare International Airport departs from Chicago O'Hare International Airport at 19:45 and arrives at Fort Lauderdale Hollywood International Airport at 23:59.
The flighttime is about 3h 14m. The distance travelled ("as the bird flies"): 873 Km. So the average speed is roughly 270 Km.
There is an 1 hour time difference between Chicago and Fort Lauderdale