There are
429 mi
from Clarksville, TN to South Elgin, IL
That's the driving distance. It would take 9 hours 20 mins to go from Clarksville, Tennessee to South Elgin, Illinois.
The flight distance (direct flight from Clarksville, TN to South Elgin, IL) is 380.83 mi.
429 mi = 691.11 kms