Beginning on May 7, 1864, the Union army tried to dislodge Confederate positions on Rocky Face Ridge, just outside Dalton, Georgia, with little success. On May 9, 1864, Union General William T. Sherman sent General McPherson and the Army of Tennessee, through the unprotected Snake Creek Gap toward Resaca, Georgia. At the same time, the Army of the Cumberland and the Army of Ohio feigned attacks on Confederate forces at Rocky Face Ridge. General Sherman’s plan was to hold the railroad and telegraph lines south of Dalton so that Confederate General Joseph T. Johnston would either evacuate his position on Rocky Face Ridge or detach a section of his army to fight Sherman on a ground that provided more of any advantage for the Union army. The plan did work. General Johnston withdrew his forces from Rocky Face Ridge early on May 13 and concentrated them on the hills around Resaca. On May 10, General Sherman sent the remainder of his army through Snake Creek Gap to reinforce McPherson’s Army of Tennessee.
The Battle of Resaca was fought May 13-15, 1864, in both Gordon and Whitfield counties in Georgia. On May 13, Union troops tested Confederate lines and pinpointed their location. The next day, full scale fighting occurred with the results generally indecisive. On May 15, the battle continued with no advantage to either side until General Sherman sent a force across the Oostanaula River, using recently received pontoon bridges, and advanced towards Johnston’s railroad supply lines. Unable to stop this movement, Johnston was forced to withdraw the Confederate army toward Adairsville, Georgia where another battle was fought on May 17.
Both William and Robert Patterson participated in the Battle of Resaca, Georgia and William Patterson’s regiment also participated in the battle at Adairsville. Total casualties in the Battle of Resaca was approximately 2,747 for the Union and 2,800 for the Confederates.