The card, which appears to have been written by a white spectator to his parents, is signed “your son Joe.” He refers to the horrific murder  in which the victim’s ears, fingers and sexual organs were severed  as the “barbecue we had last night.” He identifies himself in the crowd by placing a mark in ink about his head.

By permitting images like this one to move through the mail at all, the government tacitly endorsed lynching, along with the presumption that African-Americans were less than human. The mailings also aided a propaganda campaign that was intended to terrorize the black population in the nation as a whole, not just in the South.

Joe from Waco is no doubt long dead. But many of the people who attended lynchings as children in the 1930’s and 40’s must be still alive and walking the streets of the principal states of the lynching belt. They include Mississippi, Georgia, Alabama, Arkansas, Louisiana and Texas, all of which voted against the first black president.

The nearness of the past was fully evident not long ago in Atlanta, when the collectors James Allen and John Littlefield were trying to mount an exhibition of lynching images that had drawn a huge audience and international attention when shown at the New-York Historical Society’s “Without Sanctuary” exhibition of 2000.

Influential Atlantans equivocated. As a person familiar with the issue told me recently: “There were concerns that people in crowds were still alive. And of course, family members and relatives of those people might come in and have to say, ‘That’s my dad’ or ‘That’s my mom.’ ”