Little Rock Nine on the frontline

National Guard troops turn away a black student as she attempts to enter Central high school during the integration crisis that focused on Little Rock in 1957 Photograph: Popperfoto/Popperfoto/Getty Images

White students in Little Rock demonstrate against integration Photograph: A Y Owen/Time & Life Images

Students shout insults at Elizabeth Eckford, 16, as she approaches a line of National Guard troops, who blocked the main entrance and would not let her enter Photograph: Will Counts/Associated Press

President Dwight Eisenhower was compelled to use federal troops in Little Rock to enforce the supreme court ruling to desegregate schools Photograph: Bettmann/Corbis

Black students attending Central high school are escorted to an army car for their return home after classes Photograph: Bettmann/Corbis

101st Airborne Division enforce integration at Central high school as white students look on Photograph: John Bryson/Time & Life Images

Civil rights journalist Alex Wilson is kicked by an unidentified member of a white mob outside Little Rock Photograph: Will Counts/AP

Johnny Richmond, a student from nearby Arkansas Baptist college, is escorted through an angry crowd at Little Rock's Central high school Photograph: Bettmann/CORBIS

National Guard troops give a student and his bicycle a lift to school Photograph: Paul Slade/Getty Images

Students protest in Little Rock Photograph: George Silk/Time & Life Pictures/Getty Image

A few weeks after the desegregation of Central high school, only six of the nine black students are escorted into the school, the other three reporting in sick Photograph: Bettmann/Corbis

The Little Rock Nine, pictured left to right: Gloria Ray, Terrance Roberts, Melba Pattillo, Jefferson Thomas, Carlotta Walls, Thelma Mothershed, Minnijean Brown, Elizabeth Eckford, and Ernest Green Photograph: AP

President Bill Clinton sings with Jefferson Thomas (left) and Ernest Green (centre) during the congressional gold medal ceremony in the White House to honor the Little Rock Nine Photograph: Scott Applewhite/AP

The Little Rock Nine (left to right): Thelma Mothershed Wair, Minnijean Brown Trickey, Jefferson Thomas, Terrence Roberts, Carlotta Walls LaNier, Gloria Ray Karlmark, Ernest Green, Elizabeth Eckford and Melba Pattillo Beals stand on the steps of Little Rock's Central high school with President Bill Clinton commemorating the 40th anniversary of the school's desegregation Photograph: Reuters