The earliest versions of the 2-6-0 Mogul steam locomotives were built in 1863 by the Rogers Locomotive Works in Paterson, NJ. The design was an improvement on the then standard 4-4-0 wheel arrangement. In theory, the 2-6-0s extra set of driving wheels offered a 50% increase in tractive effort over the older design. It is estimated that well over 11,000 Mogul-type locos were built for the next 50-plus years. Like the 4-4-0 American-type locomotive that it was designed to replace, the 2-6-0 was a general-purpose steam locomotive that was found in both freight and passenger service.