Control of the river was a strategic objective of both sides in the American Civil War, forming a part of the U.S. Anaconda Plan. In 1862 Union forces coming down the river successfully cleared Confederate defenses at Island Number 10 and Memphis, Tennessee, while Naval forces coming upriver from the Gulf of Mexico captured New Orleans, Louisiana. The remaining major Confederate stronghold was on the heights overlooking the river at Vicksburg, Mississippi, and the Union's Vicksburg Campaign (December 1862 to July 1863), and the fall of Port Hudson, completed control of the lower Mississippi River. The Union victory ending the Siege of Vicksburg on July 4, 1863, was pivotal to the Union's final victory of the Civil War.