In the latter part of the summer of 1864, the Confederacy offered to conditionally release prisoners if the Union would send ships to retrieve them (Andersonville is inland, with access possible only via rail and road). In the autumn of 1864, after the Battle of Atlanta, all the prisoners who were well enough to be moved were sent to Millen, Georgia, and Florence, South Carolina. At Millen, better arrangements prevailed, and prisoners were transported by rail to the port of Savannah. After General William Tecumseh Sherman began his march to the sea and destroyed Millen, the remaining prisoners were returned to Andersonville.