Flight Hartsfield Jackson International Airport departs from Atlanta Hartsfield Jackson International Airport at 07:30 and arrives at Houston George Bush Intercontinental Airport at 08:24.
The flighttime is about 1h 54m. The distance travelled ("as the bird flies"): 1213 Km. So the average speed is roughly 638 Km.
There is an 1 hour time difference between Atlanta and Houston