On August 13, 1961, two days after construction began on the Wall, West Berlin mayor Willy Brandt sent a letter to U.S. President John F. Kennedy, warning that a “crisis of confidence” would ensue if the Western powers continued to remain passive in the face of the forced division of East and West Berlin. On August 16, 1961, a mass demonstration drew approximately 300,000 West Berliners to the square in front of Schöneberg City Hall, where protestors expressed their dismay over the construction of the Wall and the lack of a decisive response from the Western Allies. On August 18, 1961, Kennedy sent his vice president, Lyndon B. Johnson to Berlin. On arrival, Johnson was met by Berliners such as the ones captured on the photograph below. Their banner criticizes the Western Allies’ statement of protest to Moscow, which was perceived as feeble. It reads, “To the Western Powers: You Don't Stop Tanks with Pieces of Paper.”