Despite his time with Forrest, Anderson foolishly made a bet with staff surgeon J.B. Cowan that Forrest would be content to stay behind in Jackson while the attack took place He was forced to pay Cowan within a matter of hours.
During the early phase of the Battle itself, Forrest horrified Anderson by surveying the battlefield on horseback. Despite having two horses shot out from under him, Forrest paid Anderson little heed.
In the afternoon, Forrest dictated to Anderson a message demanding the surrender of the fort. This was a typical tactic used by Forrest. It was not unheard of him to actually bluff a superior force into surrendering. Forrest promised to treat the fort's garrison as prisoners of war. However, Forrest gave the task of treating to another soldier. The attempt to force a surrender failed, and the fort was stormed.
Anderson stayed by Forrest's side throughout the battle. Anderson oversaw pilfering of supplies before the Confederates rode off.
The day after the battle, Forrest ordered Anderson to return to Fort Pillow under a flag of truce to treat with any gunboats that might be present. Forrest told Anderson to allow the gunboats to gather up all the wounded they could. Anderson also requested that he bring POW Captain John Young with him.
When Anderson and Young arrived back at the fort, the gunboat USS Silver Cloud was shelling the shore. When the crew saw Anderson approach, the ship's commander, Acting Master William Ferguson came ashore to treat. Anderson proposed that there be a ceasefire until five o'clock that day to allow the crew of the Silver Cloud to carry every survivor, white and black, aboard the ship. Ferguson was initially surprised that any blacks were alived. A nearby wounded Negro, Sgt. Ben Robinson confirmed that he was still alive. When Anderson agreed to move all Confederate troops back from the outer perimeter of the fort, Ferguson accepted the proposal, although he was perturbed when he learned that no one, including Captain Young, knew how many men still lived.
After Ferguson returned to his boat, Anderson turned his attention back to Robinson. Anderson inquired about Robinson's rank. Robinson replied that he'd reached the rank by being the best soldier he could be. Anderson cooly wished that the Confederates had been able to kill more Negroes. Robinson said the same thing about the Confederates, prompting Anderson to reach for his revolver. However, Anderson checked himself.
As they day wore one, Anderson oversaw the removal of troops. He even went aboard the USS Platte Valley, and socialized with its skipper. As they talked, the Confederate troops began burning the barracks outside the fort. While Anderson assured the skipper that they weren't burning living people, the smell of burning flesh revealed that at least some corpses went up with the barracks. As they watched, a Confederate troop began shooting black soldiers, in violation of the truce. As the shooter was immediately arrested, the skipper didn't protest too much, but Anderson realized he'd worn out his welcome and returned to shore.