A transportation tunnel under the Hudson River connecting Manhattan and New Jersey was first considered in the 1860s, fueled by New York City's rapidly growing congestion and the inadequacy of existing ferry service to population centers across the river. DeWitt Clinton Haskin, an engineer formerly with the Union Pacific Railroad, started the project in 1874 and subsequently endured an extended lawsuit, several failures of the tunnel wall, and an exhaustion of funds before quitting in 1887 with only 1,600 feet completed.
The Delaware Aqueduct provided an important transportation link between the Pennsylvania's coalmines and New York's booming industrial marketplace. It is the earliest surviving work of John A. Roebling, who designed the Brooklyn Bridge 30 years later. The cable anchorage system first used on this project was also used on the Brooklyn Bridge. The aqueduct is patterned after Roebling's design of the Pennsylvania Canal over the Allegheny River, and is the oldest metal strand cable suspension bridge still standing in the U.S.