give a narrative account of the construction of the Berlin wall
-East German leader Walter Ulbricht asked Kennedy to close border from east to West Berlin
-12 August 1961 east german troops built barbed wire fence between east and west Berlin
-a concrete wall stretching 165km then built
-overtime it was reinforced with barbed wire, minefields, and car barriers
-wall could only be crossed with correct paperwork
-had a few heavily manned checkpoints