America’s current debate on its multiracial present should benefit greatly from remembering a moment from its recent past.

It was a photograph which was widely reprinted back then, but not much since; of the United States’ civil rights struggle in the 1960s and the 1970s, many iconic photos had been made, but only a handful conveys the scale of anger and hatred this photo captured on May 28, 1963.

Sitting at the whites-only counter at a Woolworth’s five-and-dime store in Jackson, Mississippi were three protestors (l. to r.): John Salter, Joan Trumpauer, and Anne Moody. All three were from Tougaloo College, a historically black college which became a centre of activity for he civil rights movement in Mississippi during the tumultuous 1950s and 1960s. Salter, a Native American who later assumed the tribal name Hunter Bear Gray, taught sociology at the college, while two girls were students there. In fact, Trumpauer (soon to be Joan Mulholland) was one of two white students at Tougaloo.

The moment was captured by Jackson Daily News photographer Fred Blackwell, who stood atop the lunch counter to take pictures. In the photo, the trio’s peaceful sit-in to integrate the department store’s lunch counter was drowned out by the angry white-mob. The mob doused the trio in ketchup, mustard and sugar — an abuse that lasted for some three hours until the manager closed the counter for the day.

Take a good look at the young man pouring sugar over Trumpauer’s neatly coiffed hair, and then at the man smoking a cigarette, and at glaring eyes of the rest of the spectators. There were looks of anger, disdain, and apathy. Unsettlingly, they were not fighting some rearguard action for segregation. The majority of the mob were teenagers and students from nearby Central High School.

It has been over half-a-century since that sit-in. With a black president in the White House, America has indeed come a long way from those dark days, but many commentators often forget that there are many for which segregation and Jim Crow are memories, not history. For each heralded memory of marching with Dr. King at Selma, there is perhaps a hidden one of dousing sit-in girls with mustard. Misguided teens they might have been, but now many members of that mob are in their seventies. Do they still hold the beliefs they so vociferously displayed on that May afternoon fifty-two years ago? It is for them to answer — but America should ask such uncomfortable questions frequently if she hopes to become a ‘post-racial’ society.