Brig. Gen. Abner Doubleday (June 26, 1819 – Jan. 26, 1893). He was a U.S. Army officer and Union general in the Civil War. He fired the first shot in defense of Fort Sumter, the opening battle of the war and saw combat action at Second Bull Run, South Mountain, and Antietam. He had a vital role in the early fighting at the Battle of Gettysburg. After the war, he continued to serve in the Army and even obtained a patent on a cable car railway. He left the Army in 1873 and became a lawyer. Doubleday is often credited with inventing baseball.