A sand bar in the mouth of Charleston Harbor was fortified with tons of New England granite to become Fort Sumter, part of the U.S. coast defenses built after the War of 1812.
Named for a Revolutionary War General, it was still unfinished when Confederate batteries opened fire on 12 April, 1861, beginning the US Civil War.
The inevitable result of what Mr. Lincoln called “the terrible arithmetic” was the surrender of the Confederacy on 9 April 1865.
Between those 4 Aprils, the toll was an estimated 620,000 lives.
Lincoln was assassinated 5 days later.