Flight O'Hare International Airport departs from Chicago O'Hare International Airport at 18:00 and arrives at New York La Guardia Airport at 21:14.
The flighttime is about 2h 14m. The distance travelled ("as the bird flies"): 1560 Km. So the average speed is roughly 699 Km.
There is an 1 hour time difference between Chicago and New York