There are
903 mi
from Clarksville, TN to Port Lavaca, TX
That's the driving distance. It would take 17 hours 10 mins to go from Clarksville, Tennessee to Port Lavaca, Texas.
The flight distance (direct flight from Clarksville, TN to Port Lavaca, TX) is 767.44 mi.
903 mi = 1,453.23 kms