There are
785 mi
from Decatur, IL to Seagoville, TX
That's the driving distance. It would take 14 hours 25 mins to go from Decatur, Illinois to Seagoville, Texas.
The flight distance (direct flight from Decatur, IL to Seagoville, TX) is 652.24 mi.
785 mi = 1,263.59 kms