Mgbe ndị agha Union n'okpuru Major General William T. Sherman bidoro ịga n'ihu na Georgia na Mee 1864, Gọvanọ Georgia Joseph E. Brown họpụtara Carswell ka ọ bụrụ brigadier general na ndị agha Georgia. Carswell duziri 1st Brigade nke ndị agha Georgia na mmegide ndị Union Army n'okpuru Sherman n'oge Atlanta Campaign na Sherman's March to the Sea. Ndị agha ahụ lụrụ ọgụ na Agha nke Ruff's Station, ugbu a Smyrna, Georgia na July 4, 1864, Agha nke Atlanta
na July 22, 1864 na n'oge nnọchibido nke Atlanta ruo mgbe ọdịda nke obodo ahụ na September 2, 1864.