Fort Sumter, South Carolina was famous for having suffered the first shots of the Civil War in April 1861. Over three years later, the two sides were still fighting over it. Confederate troops held the badly damaged fort while Union soldiers fired on it with artillery from batteries on nearby islands.
On Dec. 5 an unidentified Confederate soldier in Fort Sumter saw a Union soldier moving in Battery Gregg, 1390 yards away. The Southerner was likely using a Whitworth Rifle when he lined up his sights on the Union soldier and fired, killing him.
Fort Sumter in Sep. 1863 had already been subjected to two years of shelling by Confederate and then Union forces. After this photo was taken, it would suffer another year of shelling before the events of Dec. 5, 1864.
The Union soldiers endured the fire for an hour before they responded. They began firing cannons from the battery at Cummings Point, a group of cannons protected from retaliation by iron armor.
After an hour of shelling, the Confederates learned of the ceasefire and sent the Union general a very gracious letter of apology.
Both sides returned to the truce, but it didn't last. Charleston was still under siege and Union batteries soon resumed shelling the city. In mid-February 1865, Confederate troops withdrew from Fort Sumter and Charleston as Maj. Gen. William Tecumseh Sherman arrived on his famous march to the sea.