Henry Roe Campbell

Henry Roe Campbell (September 9, 1807 – February 6, 1879) was an American surveyor and civil engineer. Campbell contributed to American railroading and bridge-building in the first half of the 19th century. Campbell patented his 4-4-0 design in February 1836, just a few months before the patent law was changed to require that claims include proof of originality or novelty.

The 4-4-0 or American type steam locomotive was the most popular wheel arrangement in 19th century American railroads and was widely copied. White noted that the design was successful because it "... met every requirement of early United States railroads".

At the end of Campbell's career. a Harper's Magazine article in March 1879 noted that the impact Campbell's design played in railroad development in the United States when it wrote:

(Emphasis and 4-4-0 reference added.)}}

Not only did the new American Type steam locomotive deliver more horsepower, tractive effort, and reliability it also laid the groundwork for locomotive engineering in the 19th century with boilers mounted horizontally (instead of vertically), smoke stacks mounted vertically at the front to expel the smoke and cinders away from the crew and passengers.

This design also provided greater protection with an enclosed cab and many other features including things like cowcatchers, front-mounted headlamps/lights, etc.).

While Campbell's 4-4-0 design was less attractive by the end of the 19th century as more powerful locomotives took their place such as the 4-6-0 wheel arrangement and Consolidations of the 2-8-0 wheel arrangement even though some 4-4-0s remained in service into the 1940s, over 100 years after the design was initially conceived. Provided by Wikipedia