April 12, 1861 was the Confederate bombardment of Union-held Fort Sumter in Charleston Harbor, an engagement that plunged the nation into four years of war, as well as being the nation's bloodiest conflict.
About 4 a.m. Tuesday, a single beam of light reached skyward from the stone works of Fort Sumter. About a half hour later, about the time the first shots were fired, a second beam glowed, signifying a nation torn in two.
In a dispatch to The Associated Press in 1861, an unnamed correspondent observed the fort's parapets crumbling under the pounding of artillery. He wrote of gun emplacements being "shot away" and shells falling "thick and fast."
"The ball has opened. War is inaugurated ... Fort Sumter has returned the fire and brisk cannonading has been kept up," the dispatch said.
Sumter fell after a 34-hour bombardment.
Civil war re-enactors were also paying tribute to those who fought. One re-enactment was held at Patriots Point in Mount Pleasant, South Carolina last weekend.
More than 600,000 soldiers died in the Civil War.
The Associated Press contributed to this story