Editing Checkpoint Charlie (section)

==Background==
[[File:CheckpointCharlieSign1981.jpg|thumb|upright|Sign at Checkpoint Charlie on the way into West Berlin, as it appeared in 1981]]

===Emigration restrictions, the Inner German border and Berlin===
{{further information|Eastern Bloc emigration and defection|Inner German border|}}
Between 1949 and 1961, over 2½ million East Germans fled to the West.<ref name="Gedmin">{{cite book |last=Gedmin |first=Jeffrey |title=The hidden hand: Gorbachev and the collapse of East Germany |publisher=American Enterprise Institute |series=AEI studies |volume=554 |pages=35 |chapter=The Dilemma of Legitimacy |isbn=978-0-8447-3794-2 |year=1992}}</ref> The numbers increased during the three years before the Berlin Wall was erected,<ref name="Gedmin" /> with 144,000 in 1959, 199,000 in 1960 and 207,000 in the first seven months of 1961 alone.<ref name="Gedmin" /><ref name="dowty123">{{Harvnb|Dowty|1989|p=123}}</ref> The 3.5&nbsp;million East Germans who had left by 1961 totaled approximately 20% of the entire East German population.<ref name="dowty122">{{Harvnb|Dowty|1989|p=122}}</ref>

The emigrants tended to be young and well educated,<ref name="thackeray188">{{Harvnb|Thackeray|2004|p=188}}</ref> including many professionals&nbsp;— engineers, technicians, physicians, teachers, lawyers and skilled workers.<ref name="dowty122"/>The [[brain drain]] became damaging to the political credibility and economic viability of East Germany.  <ref name="pearson75">{{Harvnb|Pearson|1998|p=75}}</ref>

By the early 1950s, the [[Soviet Union|Soviet]] method of restricting [[Eastern Bloc emigration and defection|emigration]] was emulated by most of the rest of the [[Eastern Bloc]], including [[East Germany]].<ref name="dowty114">{{Harvnb|Dowty|1989|p=114}}</ref> However, in [[occupied Germany]], until 1952, the lines between East Germany and the western occupied zones remained easily crossed in most places.<ref name="dowty121">{{Harvnb|Dowty|1989|p=121}}</ref> Subsequently, the [[inner German border]] between the two German states was closed and a barbed-wire fence erected.

Even after closing of the inner German border officially in 1952,<ref name="harrison99">{{Harvnb|Harrison|2003|p=99}}</ref> the city sector border in between [[East Berlin]] and [[West Berlin]] remained considerably more accessible than the rest of the border because it was administered by all four occupying powers,<ref name="dowty121"/> so Berlin became the main route by which East Germans left for the West.<ref>{{cite book |last=Maddrell |first=Paul |title=Spying on Science: Western Intelligence in Divided Germany 1945–1961 |url=https://archive.org/details/spyingonsciencew00madd_920 |url-access=limited |pages=[https://archive.org/details/spyingonsciencew00madd_920/page/n70 56] |publisher=[[Oxford University Press]] |year=2006 |isbn=978-0-19-926750-7}}</ref>

===Berlin Wall constructed===
{{main article|Eastern Bloc emigration and defection|Berlin Wall}}
On 13 August 1961, a barbed-wire barrier that would become the [[Berlin Wall]] separating East and West Berlin was erected by the East Germans.<ref name="pearson75"/> Two days later, police and army engineers began to construct a more permanent concrete wall.<ref name="dowty124">{{Harvnb|Dowty|1989|p=124}}</ref> Along with the wall, the 830-mile (1336&nbsp;km) zonal border became 3.5 miles (5.6&nbsp;km) wide on its East German side in some parts of Germany with a tall steel-mesh fence running along a "death strip" bordered by mines, as well as channels of ploughed earth, to slow escapees and more easily reveal their footprints.<ref name="black141">{{Harvnb|Black|English|Helmreich|McAdams|2000|p=141}}</ref>