We travel to IN every couple of years and we drove out to CA a few years ago (drove
thru WI) Here are some things we've done on our trips; most are off I-90 or not to far off ;others are off I70. Which way we go depends upon our mood:
Rock & Roll Hall of Fame in Cleveland, OH
We've taken a little diversion on our trip and drove up to see a couple of the Great Lakes. A little ways out of the way. We hit Geneva on the Lake to see Lake Erie, where there is a little town park where there was a play ground and a place to walk down to the shore - again free

(there is also a state park), and on Lake Michigan we stopped in New Buffalo, where we waded in the lake toured the shops and had an ice cream.
Chicago, IL
The John Glenn Museum in OH
Cedar Point in Sandusky, OH
AND...Depending upon where you are going in NY:
Baseball Hall of Fame in Cooperstown, NY (about an hour off I90)
Niagra Falls again about an hour or 2 off I90
Fort Ticonderoga (Northern NY near VT border)
Lake Champlain (Near VT Border)
Letchworth State Park (beautiful Waterfalls)
Delaware Water Gap
HTH