Dean Cisneros (left) of Lincoln High School questions a student about throwing an orange at his teacher. Lincoln Heights

[Crowd at mall in front of Lincoln Memorial, March on Washington]

[Steps of Lincoln Memorial littered with debris after March on Washington]

[John F. Kennedy campaigning in Spokane, Washington]

David L. Lawrence, Pittsburgh mayor, reading 'The Shame of the Cities' by Lincoln Steffans

[Major Milton Wolff, commander of the American Abraham Lincoln Brigade, near Falset, Spain]

[Major Milton Wolff, commander of the American Abraham Lincoln Brigade, near Falset, Spain]

[Members of the Abraham Lincoln Brigade, farewell ceremony for the International Brigades, Les Masies, Spain]

[Members of the Abraham Lincoln Brigade, farewell ceremony for the International Brigades, Les Masies, Spain]

[Republican soldiers firing machine guns, University City, Madrid]

[Republican soldiers of the International Brigade, University City, Madrid]

[Martin Luther King Jr. addressing Prayer Pilgrimage for Freedom, in front of the Lincoln Memorial, Washington, D.C.]

[Republican soldiers of the International Brigade, University City, Madrid]