The Wrightsville Dam was a 19th century dam on the lower Susquehanna River

Susquehanna River

The Susquehanna River is a river located in the northeastern United States. At long, it is the longest river on the American east coast that drains into the Atlantic Ocean, and with its watershed it is the 16th largest river in the United States, and the longest river in the continental United...

 between Wrightsville

Wrightsville, Pennsylvania

Wrightsville is a borough in York County, Pennsylvania, United States. The population was 2,310 at the 2010 census. Wrightsville borough has a police department, historic society, and a volunteer fire company.- History :According to a plaque at Samuel S...

 and Columbia, Pennsylvania

Columbia, Pennsylvania

Columbia, once colonial Wright's Ferry, is a borough in Lancaster County, Pennsylvania, 28 miles southeast of Harrisburg on the left bank Susquehanna River across from Wrightsville and York County. Originally, the area may have been called Conejohela Flats, for the many islands and islets in the...

.

The low-head dam was constructed in 1840 to impound the waters of the Susquehanna to provide a slackwater pool to allow the safe passage of canal boats from the Pennsylvania Canal

Pennsylvania Canal

Pennsylvania Canal refers generally to a complex system of canals, dams, locks, tow paths, aqueducts, and other infrastructure including, in some cases, railroads in Pennsylvania...

 on the Columbia (Lancaster County

Lancaster County, Pennsylvania

Lancaster County, known as the Garden Spot of America or Pennsylvania Dutch Country, is a county located in the southeastern part of the Commonwealth of Pennsylvania, in the United States. As of 2010 the population was 519,445. Lancaster County forms the Lancaster Metropolitan Statistical Area, the...

) side across the mile-wide rocky river to the Susquehanna and Tidewater Canal

Susquehanna and Tidewater Canal

The Susquehanna and Tidewater Canal between Wrightsville, Pennsylvania, and Havre de Grace, Maryland, at the head of Chesapeake Bay, provided an interstate shipping alternative to 19th-century arks, rafts, and boats plying the difficult waters of the lower Susquehanna River...

 on the Wrightsville (York County

York County, Pennsylvania

York County is a county in the U.S. state of Pennsylvania. As of 2010, the population was 434,972. It is in the Susquehanna Valley, a large fertile agricultural region in South Central Pennsylvania....

) side.