In 1961, the new US president, John F Kennedy broke off diplomatic relations with Cuba.
For the Bay of Pigs Invasion, Cuban exiles were trained in the US and supported by US air power. It took place on 17 April 1961. It had originally been planned under the previous US president (Eisenhower)
The invasion was a failure because US intelligence, which thought that Cuban people would rebel against Castro, was wrong and Cuban forces knew the attack was coming