In Evansville, Indiana on a hot July 3, in 1903, a black man refusing to pay his bar tab engages in a gunfight with a police officer in the street outside the bar. The officer falls dead.

The next day, a mob of white people armed with axes and guns, converges on the jail where they think the black man is being held, intending to lynch him. They pull down a telephone pole and attempt to batter their way into the building, even after being told they are attacking the wrong jail. They are fired upon by guards, and — growing into a mob of thousands — turn to attack black people, businesses and neighborhoods instead. 12 people are dead by July 6, when the governor declares martial law and sends in the National Guard. About 2,000 of the city's 8,000 black residents move out of the city.