I finally got around to calculating all the vital info from our roadtrip.
Total miles: 7785
Gallons of petrol: 250
MPG 31.14 (I attribute this low value to the speed -- much of it over 80 mph -- and the unavailability of high octane gas west of the Mississippi)
Number of states driven through: 24
U.S. License plates spotted: 50 states plus DC
Number of national chains eaten at: 1 (we were in a hurry on the Ohio Tpk heading east, but we'll never eat at a Pizzeria Uno again.)