United States President John F Kennedy gave a speech in Berlin at the height of the Cold War on 26 June 1963.
It galvanised the world in support of West Berliners who had been isolated by the construction of the Berlin Wall.
Tom Wills speaks to Gisela Morel-Tiemann, who attended the speech as a student.
A Whistledown production for BBC World Service.
(Photo: John F Kennedy making his speech in Berlin. Credit: Lehnartz/ullstein bild via Getty Images)