On July 20, 1864, Union forces under Maj. Gen. W.T. Sherman, USA, were closing in on Atlanta. Hq. 2nd Cavlary Division (US), Brg. Gen Kenner Garrard, was in Decatur. His three brigades were scattered from Decatur to Roswell, guarding bridges over the Chattahoochee River and picketing the left flank. That night, Garrard was ordered to assemble his command and march to Covington (30 miles SE), to burn bridges over the Yellow and Ulcofauhachee (Alcovy) rivers and to destroy the railroad between Lithonia and the Alcovy.
Garrard marched late on the 21st. He returned to Decatur on the 24th, after marching almost 90 miles. He destroyed 4 wagon bridges, 2 railroad bridges and more than 6 miles of track. At Covington, he burned the depot, a newly built army hospital center, 2000 bales of cotton, and large quantities of quartermaster and commissionary supplies. Three trains were captured and burned.
Garrard's raid cut off all communication between Atlanta and Augusta and destroyed any hope that the Army of Tennessee (CS) - the hard pressed defenders of Atlanta - might receive supplies or reinforcements from Eastern Confederacy; but this success was not without its price. Because of Garrard's absence from the Union left, Hardee's Corps (CS) was able to approach undetected and launch his smashing blow at that unguarded flank which has passed into history as the Battle of Atlanta.