One practical note before anything else: this exhibit has been listed as closed on the park's own things-to-do page, along with the Civil War Museum, and lower-town exhibits here open and shut with staffing and building work. Ask at the visitor center desk on Cavalier Heights before you build an afternoon around it. Everything below is worth knowing whether or not the door is open, because the story it tells is written across the rest of the town.
Black Voices from Harpers Ferry is the park's treatment of African American life here, and it is the necessary counterweight to a town that is otherwise told through one white abolitionist and three days in October 1859. Harpers Ferry was a federal armoury town in a slave state. Enslaved and free Black people lived and worked in it, in the households, the hotels, the mills on Virginius Island and the railroad. The raid was carried out in their name, largely without their participation, and the consequences fell on them hardest.
The first person killed in John Brown's raid was Heyward Shepherd, a free Black man working as a baggage handler for the Baltimore & Ohio, shot at the railroad on the night of 16 October. That fact has been used for a century and a half to argue almost every position available about Brown, and the monument erected near the armoury grounds in 1931 by the United Daughters of the Confederacy and the Sons of Confederate Veterans is one of the more contested objects in the National Park System. The park now interprets it rather than simply displaying it, which is the right call and a hard-won one.
Then comes the part that outlasts the raid. Storer College opened on Camp Hill in 1867 to educate people freed from slavery, admitted students without distinction of race, and in August 1906 hosted the first meeting on American soil of the Niagara Movement, the organisation that became the NAACP. The delegates walked down the hill to John Brown's Fort.
That is the arc this exhibit exists to trace, and it is the reason to give Camp Hill an hour rather than a glance.