He was either a traitorous villain or a martyr for the cause, depending on which side of the Mason-Dixon line your ancestors lived.

It was 1860, and a man named James W. Jackson, a rabid secessionist, was managing the Marshall House, a hotel that once stood on the corner of King and Pitt Streets in Alexandria, Virginia. Jackson found it fit to hang an enormous woolen Confederate flag—14×24 feet—from a 40-foot mast at the top of the hotel and installed a non-working cannon behind the hotel’s tavern, aimed at the hotel’s front door. He then told people that the flag would be removed only over his dead body.

In late May the following year, the first year of the Civil War, Jackson was granted his wish. The 11th New York Infantry, better known as the New York Fire Zouaves, had just swept into Alexandria. The unit couldn’t miss the gigantic flag of their enemy atop a hotel. The unit’s commander was Col. Elmer E. Ellsworth, who had known President Lincoln back when he was just a gangly lawyer in Springfield, Illinois. Ellsworth was not going to allow that flag to fly.

He and another Union soldier, Francis E. Brownell, climbed to the roof and removed the flag. When they came back down the stairs, an enraged Jackson met them with a shotgun. Jackson fired at Ellsworth, striking him in the chest and killing him. Brownell fired his already-loaded musket at Jackson, striking him in the face. He then rammed his bayonet into Jackson’s chest. In a confrontation that took just a few seconds, two men lay dead on the stairs.

Thomas Holmes, a New York coroner who had been embalming bodies and teaching others the trade for several years, heard about the incident and discovered that Ellsworth was a friend of Lincoln. He visited the president in Washington and offered to embalm Ellsworth for free. Lincoln accepted.

Holmes used a French embalming technique in which he injected an artery in the neck or wrist with a mixture of alcohol, arsenic, creosote, mercuric chlorides, and turpentine. The embalming preserved the body long enough for it to lie in state for several days before being buried in Mechanicsville, New York, Ellsworth’s hometown.

Michael Strahan, in a post for Lost New England, wrote, “This incident at the Marshall House would mark the first Union officer to die in the Civil War. Ellsworth’s body would be sent to the White House for public mourning, while Jackson’s actions made Southerners view him as their first martyr of the war.”

Not only was Ellsworth the first Union officer killed in the war, but he was also the first casualty to be embalmed. Coroner Holmes would go on to embalm an estimated 4,000 men, mostly officers, at a fee of $100 per body. A total of approximately 40,000 embalmings were carried out during the war, out of about 750,000 killed on each side.

A newspaper at the time wrote this about Thomas Holmes:

He expresses the hope that if employed upon any one of celebrity, it will be no less a personage than Jeff. Davis. He would take especial pleasure in injecting a very large amount of embalming fluid in his veins, and rendering him as rigid as a marble statue.

Embalming changed forever when formaldehyde came into funereal use in the 1890s, but of course that’s a story for another time.