E.R. Shaw(Shaw Custom Barrels) is doing one now. It's like a build your own/semi custom rifle. I don't know that they "manufacture" all parts. IWI I believe is located in Harrisburg area. While they don't have an AR, they do sell many other popular semi-auto rifles. Once again I'm not sure that they're 'manufactured" in PA or just imported.
I would recommend Oxgoad Arms near the Pittsburgh Airport. Quality work and great prices. Chris is the owner. Reach out to them. They can also do custom Cerakote work as well. You will not be disappointed.