The easiest and and the route with the least amount of hills is
59 I 30E I 40 E I55N I 57N I70E I 270 N I 71N I 76E I 80E Might be a little longer but a lot less crazy traffic and no tolls. I HATE I 40 and I 81 !! Up hills, down hills, a ton of semis trying to drag up the hills and fly down them not to mention wall to wall cars. Some times you can't even get a break to get into the passing lane. I have driven up to NYC from Houston and the west coast steady for many years and have driven every route there is up to NJ/NYC . There are many ways to go, that one was always the easiest .
The closer you get to the east coast the more crazy traffic you get into. What ever you do don't go up I 95 or you will hit DC, Baltimore and all that mess from Delaware up through NJ.