I have a box in my office filled with hate. It contains bumper stickers, literature and t-shirts I collected while researching Confederates in the Attic, a book about Civil War memory in the South.

“Coon-ard Lines: Boat Ticket to AFRICA,” reads one '90s-era item I picked up at a store selling rebel-themed souvenirs. “This ONE-WAY ticket entitles ONE nigger” to passage to Africa, as well as “axel-grease for hair,” “chicken coop and watermelon patch on deck” and “crack and other refreshments.” (A similar version is pictured below.)

The flyer of a white supremacist group features Nathan Bedford Forrest—slave trader, fierce Confederate general, and founder of the KKK—emblazoned against a rebel battle flag. Forrest fought against “race-mixing” and the federal government’s attack on “freedom for the white people,” the flyer notes. “Today we are being recalled to defend our race and nation.”

The journal of the South Carolina Council of Conservative Citizens shows photographs in 1992 of demonstrators waving the rebel banner at pro-flag rallies. Adjoining stories carry headlines like “Malcolm X Followers Rape, Murder White Woman,” and “Charleston Rape Downplayed by Liberal Media.”

In the mid-1990s such materials were widely available and I kept them as a sort of reliquary of an unapologetic racism I believed would soon go extinct. Last week’s massacre in Charleston proved me wrong. Dylann Roof often photographed himself with rebel battle flags and cited the Council of Conservative Citizens as one of the sources for his race hatred and obsession with black-on-white crime. Before opening fire he spoke about the black rape of white women. ...