I'm going to be on the move most of the year myself; around the Fourth I'll probably be transitioning from a job site in Huntsville, AL to one in Buena Vista, CO -- so I'll be nowhere along your planned route. But if you make it as far south as Louisville, KY to hit (pardon the pun) the Louisville Slugger factory (which is something I should do myself while I'm spending so much time in Kentucky), I'd suggest a couple of additional things in Kentucky: I'm told (but again, haven't done it myself) that
the Kentucky Bourbon Trail tour is interesting; and, of course, if you haven't done the
National Corvette Museum in Bowling Green, KY, you should.
One of the things I try to do when I'm on the road during the summer months is catch my Buccos at visiting ballparks. Unfortunately, it looks like your Royals will be at home during most of the period when you're on the road (in fact, it looks like they're hosting the Pirates for three games, 20-22 July, right after you get back). The Royals will be traveling to play the White Sox on 17-19 July, which is right at the tail end of your trip, but Chicago may not be along your return path. But being a baseball fan, there's ultimately nothing preventing you from simply checking out a game, regardless of who's playing and where. PNC Park in Pittsburgh is a great ballpark to just take in a game; but again, Pittsburgh may not be along your planned route. For what it's worth, the Bucs are at home 03-12 July. If you pass through the 'Burgh, even just to take in a game at PNC Park, get back to me and I'll give you the low-down on things to see/do there.
If your return leg brings you back through Pennsylvania, you'll likely be traveling across the PA Turnpike. Given the time period during which you'll be traveling, it'll be too early for
Corvettes at Carlisle, although there will be
other car-related events taking place in Carlisle around then. Also, if you're so inclined, you could bail off at points along the Turnpike to hit such sites as the
Gettsyburg National Military Park or the
Flight 93 Memorial. If you do visit Gettysburg, you might try to
pick up some fresh peaches in nearby Chambersburg -- assuming they're being harvested then; I seem to recall they generally come in a bit later in the season. Can't beat Pennsylvania corn-on-the-cob either; you should be able to find a good supply of that around mi-July at road-side stands throughout the state; but it's best eaten as soon after you buy it as possible...
If you wind up in northeastern Pennsylvania, I'm told the
Martin Guitar factory tour is worthwhile as well.
Wherever you end up going, safe travels!