The NSA has been heavily criticized for its surveillance of international internet traffic since Edward Snowden released details of its huge operations, knowledge of which sparked global fury and was even said to have damaged relations between Germany and the United States.
But documents from 1961 released this week show that the NSA knew four days before the construction of the Berlin Wall that the border between East and West was about to be closed.
The construction of the initially makeshift Berlin Wall on August 13th, 1961, led to desperate scenes of people jumping from windows of buildings on the border - and families being separated when chance led them to be in different areas that day.
President Kennedy only found out about it that day - but his NSA agents had been tapping the East German government party SED - and on August 9th, heard of the plans to close the border. These plans could be considered "the first step in a plan to close the border", the NSA said at the time.
But this analysis was never passed to the President, according to the documents released on Thursday by the National Security Archive in Washington.
The reports say Kennedy was furious when the border was closed - and charged CIA head John Alex McCone with the task of investigating the failures of the intelligence service.
The documents also show the NSA was spying on civil rights leader Martin Luther King during the 1960s, as well as boxing champion Muhammad Ali, as well as other prominent Vietnam War opponents and journalists.