NJ to LA. There are so many places to see when you get to the North East.
Philadelphia, Baltimore, Washington DC public buildings, White House, Capitol Bldg, Smithsonian at the Mall, Washington Mnmt, The Wall, Arlington Nat Cem., and many other monuments and memorials. National Air and space mus. at Dulles airport is an excellent visit.
Take a day for this side trip in route. Take I66 west out of Washington DC to Front Royal, VA. Visit Skyline Caverns then ride the Skyline Drive south to I64. Another side trip when you get to I64 is in Charlottesville, VA. Visit Thomas Jefferson's home Monticello. Then take I64 west to I81 south. It is a beautiful ride through the Shenandoah Valley. I81 S to I40 W to Knoxville, TN.