Uniform confusion: Some Southern soldiers at Bull Run wore blue uniforms instead of Confederate gray, and some Northern soldiers wore gray instead of Union blue. They had to fight in their state militia uniforms because neither side had enough official uniforms. (If you think that caused problems, you’re right.)

Picnic gone wrong: After the battle, some of the Washingtonians who had brought picnics and watched the battle from nearby hilltops were captured by the Confederates when their carriages were stuck in the traffic jam during the retreat.