Lee's first field assignment was commanding Confederate forces in western Virginia, where he was defeated at the Battle of Cheat Mountain and was widely blamed for Confederate setbacks. He was then sent to organize the coastal defenses along the Carolina and Georgia seaboard, appointed commander, "Department of South Carolina, Georgia and Florida" on November 5, 1861. Between then and the fall of Fort Pulaski, April 11, 1862, he put in place a defense of Savannah that proved successful in blocking Federal advance on Savannah. Confederate fort and naval gunnery dictated nighttime movement and construction by the besiegers. Federal preparations required four months. In those four months, Lee developed a defense in depth. Behind Fort Pulaski on the Savannah River, Fort Jackson was improved, and two additional batteries covered river approaches. In the face of the Union superiority in naval, artillery and infantry deployment, Lee was able to block any Federal advance on Savannah, and at the same time, well-trained Georgia troops were released in time to meet McClellan's Peninsula Campaign. The city of Savannah would not fall until Sherman's approach from the interior at the end of 1864.