Every night in November 1968, National Guardsmen circled the streets in Wilmington, Delaware, armed with loaded rifles and ready to put down racial violence in the city’s most impoverished neighborhoods. Every so often, they’d stop to hassle black residents, using racial slurs to refer to the people they’d been sent to the city to subdue. 

Their job was to stop riots and looting from breaking out after the assassination of Martin Luther King, Jr.—an event that had taken place seven months earlier. Though the city’s black residents had rioted briefly after King’s murder and the mayor had requested a National Guard presence, the city was now at peace. Nonetheless, Delaware’s governor, Charles Terry, was convinced its black residents would use any chance they could get to instigate more violence, and asked the National Guard to stay.

Lasting a full year, the occupation of Wilmington was the longest military occupation of an American city in history—and the most extreme response to riots that broke out in over 100 American cities after King’s murder on April 4, 1968. It only concluded with the election of a new governor in January 1969.