I generally set the cruise control between 62 to 65 mph ... we average 50 mph (allowing for refueling, eating lunch, potty stop for driver, exchanging drivers, etc) for the day.
So travelling at our pace that would require you to be on the road for 12 hours per day ... for 3 full days to go 1800 miles.
There are lots of sights to see between MA and OKC .... for instance ... Lincoln history stuff in Springfield, IL ... the arch and the museum of western expansion in St. Louis ... the Indy 500 race track ...
2004 Winnebago Journey 39W - 2012 Buick Enclave
Present @home Home: Oshkosh, WI
We call our rig "Ernie the Journey"