RH Terre Haute Mapper
Thank you for the note.
There is already a Harrison County in Indiana: https://www.openstreetmap.org/relation/1804287
This Harrison is a small town: https://en.wikipedia.org/wiki/Harrison,_Indiana
It's a "populated place" according to USGS (citation 2 on that Wikipedia page), so giving it the town tag (as it was done ~12 years ago) is correct: https://geonames.usgs.gov/apex/f?p=gnispq:3:::NO::P3_FID:452218

I haven't been there before, but it seems like this is correct (since is other information on the Wikipedia page relating to its history, etc), so this issue can probably be resolved, since this doesn't relate to Harrison County. I'll keep it open for now just in case.
Please let me know if you have any further questions.