Excerpts from Books and Wikipedia
"The Union capture of Atlanta guaranteed Lincoln's reelection in 1864 over peace candidate George McClellan. The March to the Sea introduced total war to the modern world." [Davis: 100 Decisive Battles, p. 328]
"Sherman's March to the Sea, more formally known as the Savannah Campaign, was a military campaign of the American Civil War conducted through Georgia from November 15 to December 21, 1864 by Maj. Gen. William Tecumseh Sherman of the Union Army. The campaign began with Sherman's troops leaving the captured city of Atlanta on November 15 and ended with the capture of the port of Savannah on December 21. His forces destroyed military targets as well as industry, infrastructure, and civilian property and disrupted the Confederacy's economy and its transportation networks. Sherman's bold move of operating deep within enemy territory and without supply lines is considered to be one of the major achievements of the war." [Wikipedia]