The year is 1874. The Confederacy won the civil war almost nine years ago. These are no longer the United States of America, this is no longer the land of the free (if it ever was...). It is the land of the chained, an empire of slavery founded on racism and cruelty, ruled absolutely by the new American aristocracy, The Gentry.
This game will be an alternate history/weird western where the CSA won the civil war and the PCs are among the few remaining resistance fighters who operate the underground railroad and strike at the Gentry where and whenever they can. They call themselves Rail-Splitters after their hero Lincoln, who died a martyr's death when Lee burned Washington to the ground. Surrounded by the enemy, they fight a desperate struggle against a seemingly unstoppable evil.
So where does the weird come from? Humans are not alone in the West. The Pleistocene extinctions that happened in our world never occurred in this one meaning the West is full of giant beasts, mastodons, dire wolves, saber cats, terror birds, giant beavers, thunder birds, giant armadillos (glyptodons), giant sloth (megatherium), cave bears, camels and even stranger creatures. The native people also speak of a demon, the Wendigo or Devourer, that the white man stirred awake by his greed, a spirit plague that twists both man and animal. Although, 'civilized' peoples generally dismiss native superstitions as just that, the victory of the Confederacy does seem dependent on a series of fateful yet mysterious events, the disappearance of generals and whole armies into the wilderness.
For this game I envision a stirring story populated by well written and deliciously evil villains. You will see classic elements of the Western genre mixed with a dose of Cthulhu style horror and topped with the kind of guns, blazing desperation that is the hallmark of stories like Inglorious Bastards, Jango Unchained and Wolfenstein: The New Order. Although an RP heavy on action, I expect to see all types of characters for the Rail-splitters are not all hardened Union veterans and gunslingers, nor do they all rely purely on violence to fight against the institution of slavery.