The Battle of Fairfax Court House was the first land engagement of the American Civil War with fatal casualties. On June 1, 1861, a Union scouting party clashed with the local militia in Fairfax, Virginia, resulting in the war's first deaths in action, and the first wounding of a field-grade officer.
The Union had sent a regular cavalry patrol under Lieutenant Charles H. Tompkins to estimate enemy numbers in the area. At Fairfax Court House, they surprised a small Confederate rifle company under Captain John Q. Marr, and took some prisoners. Marr rallied his unit, but was killed, and command was taken over by a civilian ex-governor of Virginia, William Smith, who forced the Union to retreat.
The engagement is judged to have been inconclusive.