Wasn't here a battle near Washington for which the citizens of the capital went out to watch, complete with picnic lunches?
Both the Union Army and the spectators were routed.
That was the first Bull Run, July 1861, by late 1864 the war had become very mundane and was no longer a spectator sport.
Or first Manassas to the Confederacy. The picnickers expected to see the rebels quickly routed, and instead had to flee the Confederate advance.
I am told that this incident provided the springboard to success for George Custer. A lesser officer at the time, his cavalry unit helped protect fleeing civilians. Eventually he became General.