Served on board the U.S.S. Baron De Kalb, Yazoo River Expedition, 23 to 27 December 1862. Proceeding under orders up the Yazoo River, the U.S.S. Baron De Kalb, with the object of capturing or destroying the enemy's transports, came upon the steamers John Walsh, R .J. Locklan, Golden Age, and the Scotland sunk on a bar where they were ordered fired. Continuing up the river, she was fired on, but upon returning the fire, caused the enemy's retreat. Returning down the Yazoo, she destroyed and captured larger quantities of enemy equipment and several prisoners. Serving bravely throughout this action, Leon, as captain of the forecastle, "distinguished himself in the various actions."