A lesser known fact of the career of Croton Aqueduct Chief Engineer John B. Jervis [shown above], is that he was the very first to run a steam locomotive on a length of railroad track in this country. He did so as a demonstration of the motive power of a self propelled locomotive in August of 1829 as an adjunct to the Delaware and Hudson Canal in Pennsylvania, which he also built as a private enterprise to deliver coal to Philadelphia and New York City along a 100 mile plus route, connecting with the Hudson River in Kingston, NY.
The commercial success for its investors of the D&H Canal cemented his reputation with the major power brokers of the time and led to his being hired 8 years later by NYC to build the Croton Aqueduct. His long time associate, Horatio Allen, was largely responsible for the locomotive experiment, travelling to England to buy 3 steam locomotive engines, The Stourbridge Lion being the one demonstrated in Pennsylvania. Railroad technology developed rapidly from 1829, Allen and Jervis being prime movers, along with Peter Cooper, Benjamin Latrobe and others.
The following screen grabs and photos flesh out a few of the details from a well documented book published in the 1870's. The entire fascinating book can be found on the internet. Note that Allen's bio. refers to his consulting on the great East River bridge, now under construction, in the 1870's, referring to the Brooklyn Bridge.