The Union Canal extended 75 miles from the Susquehanna River at Middletown to the Schuylkill River at Reading. First proposed in 1690 by William Penn, construction on the canal did not begin until 1792, and due to fundraising issues was not completed until 1828. The canal provided a vital transportation system for coal and lumber to Philadelphia. It also boasts the oldest existing transportation tunnel in the United States. The canal was abandoned in the 1880s, though portions of it remain visible today.