won a decisive victory—the first battle with the high casualty rates that would repeat over and over. The Confederates lost Albert Sidney Johnston, considered their finest general before the emergence of Lee. One of the early Union objectives in the war was the capture of the Mississippi River, to cut the Confederacy in half. The Mississippi River was opened to Union traffic to the southern border of Tennessee with the taking of Island No. 10 and New Madrid, Missouri, and then Memphis, Tennessee. In April 1862, the Union Navy captured New Orleans. "The key to the river was New Orleans, the South's largest port [and] greatest industrial center." U.S. Naval forces under Farragut ran past Confederate defenses south of New Orleans. Confederate forces abandoned the city, giving the Union a critical anchor in the deep South. which allowed Union forces to begin moving up the Mississippi. Memphis fell to Union forces on June 6, 1862, and became a key base for further advances south along the Mississippi River. Only the fortress city of Vicksburg, Mississippi, prevented Union control of the entire river. Bragg's second invasion of Kentucky in the Confederate Heartland Offensive included initial successes such as Kirby Smith's triumph at the Battle of Richmond and the capture of the Kentucky capital of Frankfort on September 3, 1862. However, the campaign ended with a meaningless victory over Maj. Gen. Don Carlos Buell at the Battle of Perryville. Bragg was forced to end his attempt at invading Kentucky and retreat due to lack of logistical support and lack of infantry recruits for the Confederacy in that state. Bragg was narrowly defeated by Maj. Gen. William Rosecrans at the Battle of Stones River in Tennessee, the culmination of the Stones River Campaign. Naval forces assisted Grant in the long, complex Vicksburg Campaign that resulted in the Confederates surrendering at the Battle of Vicksburg in July 1863, which cemented Union control of the Mississippi River and is considered one of the turning points of the war. The one clear Confederate victory in the West was the Battle of Chickamauga. After Rosecrans' successful Tullahoma Campaign, Bragg, reinforced by Lt. Gen. James Longstreet's corps (from Lee's army in the east), defeated Rosecrans, despite the heroic defensive stand of Maj. Gen. George Henry Thomas. Rosecrans retreated to Chattanooga, which Bragg then besieged in the Chattanooga Campaign. Grant marched to the relief of Rosecrans and defeated Bragg