Credit: Library of Congress
Designed and built by Captain Richard Delafield of the U.S. Army Corps of Engineers, the Dunlap Creek bridge was the first cast iron bridge built in the United States. Completed in 1839, soon before the federal government turned control of the National Road over to the states, the 80-foot bridge is still in use today with no weight restrictions. Sidewalks, with bracing and horizontal beams underneath, were added to the original arch bridge in 1921.
