The Monocacy Aqueduct which is sometimes referred to as The C&O Canal Aqueduct No. 2 is the largest Aqueduct on the Chesapeake and Ohio Canal. It crosses the Monocacy river before it empties out into the Potomac River. This takes place in Frederick County, Maryland.
The Monocacy Aqueduct was built between they years of 1829 and 1833 by 3 different contractors. The project's total cost was $127,900 and it covers 438 feet.
During the Civil War this was used by the Union to get goods in and out of Maryland. Because the Confederates knew this aqueduct was important to the union, they constantly attacked it and it became a vocal point of the Civil War. The Confederate Soldiers tried to destroy the aqueduct on several occasions but were unsuccessful.
After a natural disaster threatened the aqueduct, the support structure was replaced with steel to ensure the aqueduct would stay standing.