United States trained Cuban exiles to Cuba. Fidel Castro helped to lead the Cuban revaluation in over through ing the existing government of Cuba in 1959. He was a ardent communist and was a allied with the Soviet Union. This deeply concerned the United States as this gave communism and Soviet Union a foothold in the Americas. This happened in Cuba on April 17 1961.The invasion occurred on April 17, 1961. It didn't go well. The Cuban air force was hit by early air strikes there were still planes left to attack the invaders. Once the invasion started, it took too long for the troops and ammunition to get off the ships. Before the ammunition could be unloaded, Cuban planes sunk the invader's ships.