There are
1,391 mi
from Harlingen, TX to Markham, IL
That's the driving distance. It would take 1 day 1 hour to go from Harlingen, Texas to Markham, Illinois.
The flight distance (direct flight from Harlingen, TX to Markham, IL) is 1,206.94 mi.
1,391 mi = 2,238.27 kms