The Soviet blockade of Berlin lasted from June 24, 1948, to May 12, 1949, a period of nearly 11 months. During this time, the Soviet Union cut off all land and river transit between West Berlin and West Germany in an attempt to force the Western Allies to abandon their jurisdictions in West Berlin
. The blockade ended on May 12, 1949, when the Soviet Union lifted the blockade after sustained Western airlift efforts and economic countermeasures
. The Berlin Airlift, which supplied West Berlin by air during the blockade, continued until September 30, 1949, to build up surplus supplies
