Henry Roe Campbell

Henry Roe Campbell (September 9, 1807 – February 6, 1879) was a prominent American surveyor and civil engineer. Campbell made significant contributions to American railroading and bridge building in the first half of the 19th century being known as the known as "The Bridge builder of New England" as well as the inventor of the 4-4-0 steam locomotive. 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...

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.

Henry Roe Campbell was born on September 9, 1807 in Woodbury, New Jersey to Amos Campbell, (1779 in Bucks County, Pa; died 1868) and Ann Roe . Amos Campbell was a bridge builder and of Scottish descent, settled in Pennsylvania in 1837. His mother's family, the Roe's were among the early settlers of New Jersey. Henry was one of nine children in the family, Henry's brother John D. Campbell, (b. 1821, d. 1863) would also go on to becoming a civil engineer while helping his brother Henry construct bridges for the Vermont Central Railroad and then went on to become Superintendent of the Michigan Southern and Northern Indiana Railroad.
Henry Roe Campbell married Sidney Boyd of Lancaster, Pa. in 1833. Henry met Sidney while he worked on the Philadelphia & Columbia Railroad. Two are their sons were Joseph Boyd Campbell (1836-1891), a graduate of West Point (Class of 1861) and civil war veteran (Battle of Antietam) and Henry Roe Campbell, Jr., who was also involved in railroads and civil engineering.