There are
406 mi
from Clarksville, TN to Downers Grove, IL
That's the driving distance. It would take 8 hours 45 mins to go from Clarksville, Tennessee to Downers Grove, Illinois.
The flight distance (direct flight from Clarksville, TN to Downers Grove, IL) is 366.41 mi.
406 mi = 653.84 kms