Photographs capture a moment in time. And some of the best pictures demand that viewers not only ask questions about why the photo packs such an emotional wallop, but also about what happened before and after it was taken. A photograph...

A powerful photograph of the Freedom Riders of 1961 launches an examination of the de jure and de facto injustices that the civil rights movement of the 1950s and 1960s addressed. Young historians first watch a video and read the Supreme...