The Duckport Canal was an unsuccessful military venture by Union forces during the Vicksburg campaign of the American Civil War. Ordered built in late March 1863 by Major General Ulysses S. Grant, the canal stretched from the Mississippi River near Duckport, Louisiana, to New Carthage, Louisiana, and utilized a series of swampy bayous for much of its path. It was intended to provide a water-based supply route for a southward movement against the Confederate-held city of Vicksburg, Mississippi, as high water levels made overland travel difficult. Manual digging was provided by 3,500 soldiers from Grant's army and was finished on April 12. The next day, the levee separating the canal cut and the Mississippi River was breached, and water flowed into the canal. Trees that had grown up in the bayous and falling water levels that reached as shallow as 6 inches (15 cm) at one point hampered the use of the canal, and the project was abandoned on May 4. Grant moved men and supplies through the overland route, which had been made more accessible by the same falling water levels that doomed the canal. After some inland maneuvering and a lengthy siege, Vicksburg surrendered on July 4, marking a significant turning point in the war.