There are
266 mi
from Clarksville, TN to Cahokia, IL
That's the driving distance. It would take 5 hours 2 mins to go from Clarksville, Tennessee to Cahokia, Illinois.
The flight distance (direct flight from Clarksville, TN to Cahokia, IL) is 209.58 mi.
266 mi = 428.71 kms