snakeman879, corn snakes have a lot more yellowish-tinge to them.
I personally do not think either the milks or the corns look like copperheads, having kept all of them. The copperhead body shape is more triangular and much wider, the head is arrow-shaped and the patterns are very different.
Here is a page comparing copperheads to other native non-venomous PA reptile species. Hope it helps you see the differences.
Northern Copperhead