Abner Doubleday was a career United States Army officer and Union major general in the American Civil War. He fired the first shot in defense of Fort Sumter, the opening battle of the war, and had a pivotal role in the early fighting at the Battle of Gettysburg. Gettysburg was his finest hour, but his relief by Maj. Gen. George G. Meade caused lasting enmity between the two men. In San Francisco, after the war, he obtained a patent on the cable car railway that still runs there. In his final years in New Jersey, he was a prominent member and later president of the Theosophical Society.

The Battle of Fort Sumter was the bombardment of Fort Sumter near Charleston, South Carolina by the South Carolina militia. It ended with its surrender by the United States Army, beginning the American Civil War.