East Germany Seals Berlin with a Wall

At midnight on August 13, 1961, East German police and armed forces began severing communication between East and West Berlin. By the arrival of morning, workers and troops had strung barbed-wire entanglements along the perimeter of the three Western occupation sectors and torn up adjoining roadways to block vehicular movement. In Germany, the date became known colloquially as Barbed Wire Sunday. Within days, concrete slabs and blocks began replacing the initial wire fences, transforming a divided metropolis into an enclosed enclave.

The partition emerged from escalating post-war tensions that had previously flared during the 1948 blockade, an event that had prompted Western allies to organize the massive Berlin airlift to sustain the city. In the years following the formal division of Germany into two rival states, the inner German frontier had closed in 1952, leaving Berlin as the primary remaining conduit for travel between East and West. Between the foundation of the German Democratic Republic and the summer of 1961, approximately three and a half million East Germans had left for the West, many of them through the city, representing roughly twenty percent of the nation's total populace.