The first American built steam locomotive, the Tom Thumb, was designed and built by Peter Cooper in 1830. To convince the newly formed Baltimore and Ohio Railroad to use steam engines there was an impromptu race between the Tom Thumb and a horse-drawn car. Although the horse won because the Tom Thumb suffered a mechanical issue the demonstration was a success, and the following year the railroad committed to using steam locomotives.
Source: Eyewitness to History.com, By Bureau of Public Roads, U.S. Department of Commerce [Public domain], via Wikimedia Commons, By Brown Brothers [Public domain], via Wikimedia Commons
