Cumberland Dam - Credit: Wikimedia Commons
The Cumberland Dam was a dam that was built across North Branch of the Potomac River in Cumberland, Maryland, for the purpose of diverting water from the river into the head of the Chesapeake and Ohio Canal. The Chesapeake and Ohio Canal Company began construction of Dam No. 8 in 1837 and work proceeded intermittently, finally concluding in 1850. The dam impounded water over a distance of a mile, causing back water for about up the river. Above the dam is the mouth of Wills Creek. Read more on Wikipedia
Source: en.wikipedia.org