Fidel Castro led a revolution in July of 1959, he overthrew Fulgencia Batista in the process. Castro turned Cuba communist and that upset the United States, so they split up and Dwight Eisenhower imposed trade restrictions on Cuba. The Bay Pigs invasion was a failed military invasion of Cuba. It's purpose was to attempt to overthrow Castro. In July of 1962, Nikita Khrushchev sent two spy planes and they secretly photographed nuclear missile sites being built. President JFK placed a ring of ships around Cuba after discovering missiles in Cuba. After that the world feared a nuclear war or the start of WWII. President JFK and Nikita Khrushchev agreed the Soviets would dismantle the weapon sites in exchange for a pledge from the United States not to invade Cuba.