In January 1863 DuBose was promoted to the rank of colonel, and commanded the regiment. DuBose and his Georgians served under Brigadier General Henry L. Benning in Major General John B. Hood's division of James Longstreet's corps, including in the Siege of Suffolk. At the Battle of Gettysburg on July 2, 1863, his regiment participated in Hood's attack on the Union III Corps, fighting at Devil's Den.