Hi John,
I used to hunt arrowheads here in eastern Ohio, but can't get out much anymore. Here the most common flint or chert used by Native Americans from the Paleo period through late prehistoric was Upper Mercer flint from around Coshocton. Upper Mercer can be anywhere from dull course gray to glossy black, blue, or even reddish. The classic Ohio Flint Ridge flint wasn't quite as common, it is various colors.
There are also many points and tools made from unidentifiable flint.
I have only seen a few gunflints found in eastern Ohio and those were all gray/black British flint.
I'm thinking that the Atlanta Arsenal flints in the flyer that Jim posted were possibly imported from France and I wonder if they might have been in storage for years before the Civil War.