War between the Central European Powers (Germany, Austria-Hungary, and allies) on one side and the Triple Entente (Britain and the British Empire, France, and Russia) and their allies, including the USA (which entered in 1917), on the other side.
The closing of entry to Berlin from the west by Soviet Forces from June 1948 to May 1949; It was an attempt to prevent the other Allies (the USA, France, and the UK) unifying the western part of Germany. MORE
German-born US theoretical physicist who revolutionized our understanding of matter, space, and time with his two theories of relativity; In 1939, Einstein used his reputation to draw the attention of the US president to the possibility that Germany might be developing the atomic bomb. This prompted US efforts to produce the bomb, though Einstein did not take part in them.