The halfway point between Jacksonville, Florida and Sandusky, Ohio is Estatoe, North Carolina (depending on your exact route of course.
The halfway point between Hartford, Connecticut and Racine, Wisconsin is at Youngstown, Ohio. The journey is a total of 965 miles with Youngstown, Ohio being about 430 miles from each town.
Ashland, OH and Wooster, OH
173 miles
According to Google Earth - mid point would be around Youngstown, Ohio
Pineton, Pennsylvania is halfway between Ohio and Asbury
Sugar Grove, Ohio is the halfway point.
402 miles
592 miles
It is 279 miles according to Google Maps.
Dayton Ohio
Silver Springs, OH is the halfway point.