Plaquemine Bayou, a distributary of the Mississippi River, was a navigable waterway for centuries until after the Civil War when a levee built to prevent flooding sealed off the mouth of the bayou. In 1909 the Plaquemine Locks were completed, and this shortcut from the Mississippi into the interior of Louisiana was restored. After 52 years of service the locks closed in 1961, their operations taken over by a larger set of locks upriver at Port Allen.