Indiana would have similar town naming conventions as my state, Wisconsin, so there are a few areas you could focus on. I think a lot of them have been mentioned.
After homelands- We have Brussles, Denmark, Scandanavia, Pella (Macedonian capital under Alexander the Great, I think), Berlin (but stress is switched with Berlin, Ger.), Luxemburg, New London, Verona, Rhinelander
After people who are important to the area- Seymour- land speculator in area, owned much of Seymour; Nichols- moved here, hoping to found a great city, only 300 or so people here; Oshkosh- Winnebago chief;
Geography related- Green Bay was originally Le Baye (the bay), Wisconsin Dells and Wisconsin Rapids for sections of rivers, Milwaukee is also a river
Indigenous names- Oshkosh, Wausau, Nakoosah, just find a website that will show you what words mean, and find one that sounds good.
Foreign words- as long as it fits the area's history- Eau Claire, La Crosse, Fond du Lac (Bottom of the lake, not a cool translation, but it is at the bottom of a lake) Prairie du Chein,