The original John Bull was built in 1831 by Robert Stephenson & Co. of Newcastle, UK, for the Camden and Amboy in an 0-4-0 configuration. Officially named the "Stevens" for railroad president Robert Stevens, the train crews began to call it the "John Bull" because of its English origin.

As built, the locomotive lacked both a 'cowcatcher' and a cab. The rigid 0-4-0 design caused derailments. A set of leading wheels were added and the front two 'drivers' were uncoupled, converting the locomotive to a 4-2-0 Jervis. Later, the cowcatcher and cab were added.

The replica shown here was built by the Pennsylvania Railroad in 1940. It is on display at the Railroad Museum of Pennsylvania in Strasburg, Pennsylvania. The original is on display in the Smithsonian Institution.

The "John Bull" has 54" drivers, weighs 22 tons (with tender) and is 36' 3.5" long (with tender.)