A bus was burned. Protesters were beaten unconscious by racist mobs. But the Freedom Riders who integrated the interstate bus system in the South kept coming until they scored a decisive victory in 1961. It was one of the most important civil rights protests in American history.

The Freedom Riders’ history is on display in a traveling exposition set up in the lobby of the U.S. Courthouse in Minneapolis through June 20. If you have an hour, it’s worth your time.

The display, a mix of photographs, news clippings and explanatory panels, documents how 400 Freedom Riders, young and old, black and white, male and female, rode the buses and risked their lives to end segregated seating on interstate buses and segregated waiting rooms and restrooms at bus stations in the South. Bring your cellphone, switch it to Wi-Fi in the lobby, and listen to interviews with people connected to these actions. Some of the photos and accounts are chilling.

The exhibit does not sugarcoat the role of the Kennedy administration, which waffled and tried to dissuade the Freedom Riders from continuing their nonviolent protests.

The U.S. District Court in Minneapolis sponsored the exhibit’s stop here, and Chief Judge Michael Davis hailed the protesters’ courage and sacrifice at a ceremony last week. Other speakers included U.S. Rep. Keith Ellison and longtime civil rights advocate Josie Johnson.

Attending were four Freedom Riders from Minnesota: Robert Baum, Claire O’Connor, David Morton and Peter Ackerberg. Gene Uphoff could not attend the ceremony. Two riders, Marv Davidov and Zev Aelony, are deceased, but Aelony’s widow, Karen Olson Aelony, attended.

Before his death, Davidov told me how proud he was to be a Freedom Rider.

The exhibition was created by the Gilder Lehrman Institution of American History, based on a 2011 PBS broadcast of the documentary film “Freedom Riders,” directed by Stanley Nelson. It will air on TPT 2 at 8 p.m. Tuesday.