The seven gunboats and fifty-nine troop transports commanded by Rear Adm. David D. Porter departed Memphis, Tennessee, on December 20, stopped at Helena, Arkansas, to pick up additional troops, and arrived at Milliken's Bend above Vicksburg on December 24. After advancing up the Yazoo River, the transports disembarked Sherman's men at Johnson's Plantation, opposite Steele's Bayou, north of the city. (Preceding the landing, the U.S. Navy conducted torpedo clearing operations on the Yazoo, during which the ironclad USS "Cairo" was sunk.)