There are
854 mi
from Overland Park, KS to Slidell, LA
That's the driving distance. It would take 15 hours 53 mins to go from Overland Park, Kansas to Slidell, Louisiana.
The flight distance (direct flight from Overland Park, KS to Slidell, LA) is 662.43 mi.
854 mi = 1,374.62 kms