At the Battle of the Wilderness, General Ulysses Grant was interrupted in conversation with an aide to request use of an ambulance for a civilian doctor to visit the field hospitals. Grant refused repeatedly until he was told that the doctor was William Thomas Green Morton, the dentist who first demonstrated the use of ether. Grant said, "You are right, Doctor, he has done more for the soldier than any one else, soldier or civilian, for he has taught you all to banish pain. Let him have the ambulance and anything else he wants." In the autumn of 1862, Morton joined the Army of the Potomac as a volunteer surgeon, and applied ether to more than two thousand wounded soldiers during the battles of Fredericksburg, Chancellorsville, and the Wilderness. Here is Morton's paper on the use of ether on the battlefield.