Originally published in Rail Gamer Magazine, the Wabash Cannonball Variant is an expansion for 1830: Railways and Robber Barons. It was later commercially published in Wolfram Janich's 1830: Variant Box #1 and periodically reprinted by Winsome.
The Wabash Expansion consists of:
1) an extension the map to the west and south-west, pushing Chicago and the America west red areas a few hexes further out
2) adds a gray city north of the NYC home (not in the 2010 Winsome edition)
3) adds a few extra tiles to the mix
4) adds some trains
5) replaces the diesels with 7 trains (pictured as Challengers)
6) adds $2000 to the bank
7) adds another railroad corporation–the Wabash.
The Wabash is available at the start of the game like the other corporations. Its starting city is located on the Western area of the map near Chicago.