Too far for that age group.
Pshaw. And that's not what he asked.
Kids that age are not big on history or scenic drives.
Have you ever been to Maine? There are beaches, amusement parks, zoos, fairs, etc.
Dolbss, with kids that age I would find a halfway point and drive to that the first day, spend a day (maybe two) and then continue and reverse on the way back. Southern Maine is a great spot for kids-the beaches there are very nice, York's Wild Kingdom is a combination zoo/amusement park just perfect for kids that age. The family campgrounds in the area will have lots of kids activities. If you choose the Acadia NP area the Bar Harbor KOA is great for kids. Sand Beach in the park has ice cold water but great sand for digging. There are carriage rides in the park that they would enjoy. Try this website for kid's activities: http://www.barharborinfo.com/Things-to-Do/Family-Activities.aspx
You don't say where in Ohio you live but with a full two weeks you should be OK, especially if you break up the travel days.