The first 4-2-0 was built for the Mohawk and Hudson Railroad in 1832. It was named Experiment and then later renamed Brother Jonathan. The design was based on one by John B. Jervis. The 4-2-0 became popular in the USA as a replacement for the early 0-4-0s. The 4-2-0 design proved to be more stable than the 0-4-0.
John B. Jervis was the designer for both the Delaware & Hudson and the Saratoga & Schenectady railroads. These two railroads were connected via America's very first junction which was in Schenectady.
More details can be found here.
|No.||Class||F.M. Whyte||Gauge||Railroad Line||Location||Status||Builder Info||Notes|
|13||4-2-0||4'-8½"||B&O||B&O Railroad Museum, Baltimore, MD||operational||B&O (Mount Clare), 1927||Replica. Named Lafayette.|
|4-2-0||4'-8½"||NJ RR||Mad River & NKP Railroad Museum, Bellevue, OH||display||B&O (Mount Clare), 1904||Named Sandusky, replica. Original built in 1837 by Rogers?|
|7||4-2-0||4'-8½"||C&NW (U&S)||Chicago History Museum, Chicago, IL||display||Baldwin #37, 1837||Named Pioneer, oldest surviving C&NW steam locomotive.|
|4-2-0||5'||Raleigh & Gaston||Tornado Locomotive Building, Hamlet, NC||display||Non-functional replica named Tornado.|