Karen! Yeah, that’s a biggin’! Although we are within the range of black racer snakes, based on the snake’s length and body build per your description and photo, this would be an Eastern rat snake according to the Ohio Department of Natural Resources Reptiles of Ohio Field Guide (available from wildohio.gov).
Until recently, these were known as black rat snakes. But advances in genetics have seen a reclassification resulting in much controversy among herpetologists (reptile scientists) which may or may not be settled. So, suffice to say, your big beauty is a rat snake which, by the way, are good mousers. They are not aggressive towards humans unless taunted or assaulted. Thank you for your inquiry Karen!