Who was the first officer to die in the American Civil War?

The first person killed in the American Civil War was Elmer E. Ellsworth (May 24, 1861) — Union officer Ellsworth was a law clerk under Abraham Lincoln and an Army soldier. Just prior to the Civil War, he began recruiting for the 11th New York Volunteer Regiment. The day after Virginia voters ratified the state convention’s decision to secede from the Union, Ellsworth and his troops entered Alexandria, Virginia, to assist in the occupation of the city. There, while taking down a Confederate flag, he was shot point blank by innkeeper James Jackson, a defender of slavery. Noting his close relationship with the Lincolns, Ellsworth’s body was brought back to the White House, and his casket sat in the East Room. The funeral was attended by both Abraham Lincoln and his wife.