That depends enormously on two things: (1) where in Tennessee, and (2) Lewiston, Maine, or Lewiston, Idaho.
According to Google, it's2,597 mi - about 1 day 16 hours by car.
It is 179 miles taking this route:Take U.S. 93 NORTH, from Jackpot, to I-84 WEST to BOISE, in Twin Falls, IDAHO.Take I-84 WEST to Boise.
There is about 107 miles between Bangor and Lewiston....which is nearly a 2 hour drive.
Lewiston, Idaho to Gold Beach, Oregon is 11 h 7 min (643.2 mi) via I-84
267 miles
570 miles
between 34 and 35 hours
256 miles
256 miles
36 miles
It is 1,486.81 miles according to MapQuest.