Elkin, North Carolina
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
According to Google Earth - mid point would be around Youngstown, Ohio
173 miles
Pineton, Pennsylvania is halfway between Ohio and Asbury
Sugar Grove, Ohio is the halfway point.
Silver Springs, OH is the halfway point.
Dayton Ohio
402 miles
Somerset, Pennsylvania is about halfway between Cleveland Ohio and Columbia Maryland
The halfway point between Dallas, Texas and Warren, Ohio is in Centerville, Tennessee.