The last remaining lock of the original Chesapeake & Delaware Canal is in Battery Park in Delaware City. The lock was built in 1825, and was rebuilt in 1854 when it was widened and lengthened. In the distance is Fort Delaware on Pea Patch Island, built in the 1850s with the threat of the Civil War looming, to protect shipping centers of Philadelphia and Wilmington. Photo by xzmattzx.