In England, the 4-2-0 was developed around 1840 from the 2-2-2 design of Stephenson's first Long Boiler locomotive, which he had altered to place two pairs of wheels at the front to improve stability, with the outside cylinders between them.

An automatic version was patented in 1835 by George E. Sellers and was used extensively by locomotive builder William Norris after he obtained rights to it.

[1][2] A more practical solution, first put into production by Norris, relocated the driving axle to a location on the frame in front of the locomotive's firebox.

However Norris's design led to a shorter wheelbase, which tended to offset any gains in tractive force on the driving axle by reducing the locomotive's overall stability.

A number of Norris locomotives were imported into England for use on the Birmingham and Bristol Railway since, because of the challenges presented by the Lickey Incline, British manufacturers declined to supply.

Campbell's locomotive was estimated to be able to pull a train of 450 short tons (410 t) at 15 mph (24 km/h) on level track, outperforming the strongest of Baldwin's 4-2-0s in tractive effort by about 63%.

However, the frame and driving gear of his locomotive proved to be too rigid for the railroads of the time, which caused Campbell's prototype to be derailment-prone.

[1][2] As the 1840s approached and more American railroads began to experiment with the new 4-4-0 locomotive type, the 4-2-0 fell out of favor since it was not as capable when pulling a load.

There were possibly fears about their stability and with a long rigid frame, greater speed was achieved, albeit at the cost of a very rough ride and damage to the track.

[4][5] The prototype was a modified Dennis tractor which was fitted with a removable bogie between the front wheels to lift them high enough to prevent ground contact.

Without the bogie, the vehicle could still be driven on ordinary roads and had the advantage of being able to be detached and run around the train, without requiring special loops for that purpose.