Black Diamond Railroad The Black Diamond was an unsuccessful attempt to build a railroad from the Ohio River valley through Rabun Gap to the Atlantic coast. It was promoted by Albert E. Boone, "the Railway Pathfinder," in the late 1890s. (See also Blue Ridge Railroad.) 1896 map of the projected route in northern Georgia (41K)   Georgia's Railroad History & Heritage. Copyright, Steve Storey. Railroad History | The Depot List | Locomotives On Display | Odds & Ends | Sources & References | Home