Elnathan Sweet (November 20, 1837 – January 26, 1903) was an American civil engineer and politician from New York.
From 1864 to 1868, he was at Franklin, Pennsylvania, engaged in the engineering development of oil wells and coal mines.
He died from heart disease at the Fort Orange Club in Albany, New York, on January 26, 1903, at age 65.
[6] Of those engineering projects with which Sweet was directly involved, the Hawk Street Viaduct may have had the most lasting and widespread impact.
[3] In the years following its completion, major cantilever arch bridges were erected over the Seine and Viaur in France, the Elbe–Lübeck Canal at Mölln in Germany, and on railways in Alaska and Costa Rica.