Recently I have discovered very interesting board wargame series "Pub Battles". They have made 4 battles so far and one of them is Antietam, which fits to War of Rights scope:
http://www.commandpostgames.com/product/antietam/

I have purchased the Marengo one and I can really recommend it regardless the higher price tag. While the game itself is quite light and it is definitely not fur rule lawyers, it is really beautiful and playable. It is the only game I know in which you play on actual historical map. The thin wooden pieces look wonderful while on the map and the game provide overall enjoyable experience. I have exchanged some e-mails with the author and after the discussion, our group will use some houserules to make the game more complex and "heavy".