Greetings Cosmic Americans!
Who has the unfortunate distinction of being the first officer killed in the Civil war - none other than Elmer E. Ellsworth.
Ellsworth was a New Yorker and an attorney in civilian life, he raised and commanded the 11th New York Volunteer Infantry (the Fire Zouaves) at the beginning of the war, and he was a personal friend of Abraham Lincoln.
Here's how it all went down. On May 24th 1861 - the day after Virginia's voters ratified their state's secession, President Lincoln noticed a huge Rebel flag flying over an inn in Alexandria Virginia...just across the Potomac from Washington City.
Ellsworth, who had worked at Lincoln's law firm, helped in his presidential campaign, and who had accompanied the president to Washington, offered to go over and take care of things - which he then proceeded to do.
He led the 11th into Alexandria, deployed his men in various places in town, and took four men to the Marshall House Inn to remove the heinous banner. When he came down the Inn's stairs with flag in hand, Inn keeper James W. Jackson unloaded a shotgun into Elsworth's chest - killing him on the spot. A Union corporal - Francis Brownell - in turn killed Jackson. (He later won the Medal of Honor for this).
Lincoln, extremely saddened by the death of his friend, ordered an honor guard to carry him to the White House - where he lay in state in the East Room before returning to New York - where thousands came to visit his body at New York City' s City Hall. He is buried in Mechanicville.