The history of Nuclear Energy is built on different scientists whose research helped in it's development. In 1789, German chemist, Martin Klaproth discovered uranium, a heavy metal that can be used for a source of energy. After the discovery of uranium, radioactivity was made known in 1896 by Henri Becquerel. who was studying x-rays. During his research he used photographic plates wrapped in black pepper, to his surprise the images on the photographic plates remained clear and developed proving that uranium emitted radiation without the the use if the sun's energy. In 1932, the neutron was discovered, a particle with no electrical charge. The many discoveries and developments sparked interest in laboratories, many scientists worked to prove that fission released a chain reactions leading to a large release of energy. A major group in the the research of nuclear fission was the Perrin's group in Paris who experimented with nuclear fission with demonstrations..
In early 1939, the world's scientific community learned that German scientists discovered how to split a uranium atom. Albert Einstein fled from the Nazi regime to the United States, wrote a letter to the President of the United States urging for the United states to begin atomic research. The Manhattan Project was created, it's purpose was to create and design an atomic bomb. By the summer of 1945, the first bomb was ready to be tested. The bomb was discharged and a large mushroom cloud was created, destroying windows of civilian homes up to 100 miles away, the project was successful and the world had entered the nuclear age. After the Allied power had defeated Germany, Japan was reluctant to accept defeat. President Truman ordered an atomic bomb to bring the war to an end. The bombs "Little Boy" and "Fat Man" were dropped above Hiroshima and Nagasaki resulting in the destruction of the cites and the death of hundreds.
After World War 2, tensions between the Soviet Union and United Sates grew. They both wanted to create a more destructive bomb than the other. With the fear of nuclear war people began to build shelters and schools and other public places practiced attack drills. In 1989. the Soviet Union influence in Eastern Europe began to war off, and the government was replaced with a non-communist one. In November of 1989 the Berlin Wall as well as the Soviet Union had fallen leading to the end of the Cold War.