Hello,
I am working on my family tree and have discovered that my great-great grandfather had been adopted after the death of his parents. They lived in either WV or Ohio, does anyone know of a way to track down an adoption that old?

Most likely no, a lot of those were never done though the courts even.

If it occurred 1850 or after, I would check every census record of his adoptive family. He may have been listed under his birth name. People sometimes were. It is a long shot, but something I would definitely try. And his middle name might have been his birth name. You can check census records for a surname of that middle name for him prior to his parents death if his middle name was a possible surname. Often children were adopted by close relations, so I would also look for census records prior to his adoption for him in anyone living in the same town with the surname of his adoptive parents (including the woman's maiden name)