The Bay of Pigs Invasion was launched by the CIA-sponsored paramilitary group Brigade 2506.
The invasion saw over 1,400 American-trained Cuban exiles attempt to overthrow Fidel Castro. Castro had come to power in 1959 during the Cuban Revolution which toppled the previous president, General Fulgencio Batista. The new government quickly began introducing agrarian reforms and nationalising US-owned interests. These actions led to the USA imposing a trade embargo against Cuba from late 1960, after which Castro began to further develop his relationship with the USSR.
As concerns grew over these developments, US President Dwight D. Eisenhower authorised the CIA to begin devising a way to overthrow Castro. He allocated $13.1 million for them to begin training counter-revolutionary Cuban exiles and, on 4 April 1961, his successor John F. Kennedy authorised the final invasion plan.
While the seaborne invasion force gathered in Guatemala, a smaller group of Cuban exiles attacked Cuban airfields on 15 April using CIA-obtained B-26 bombers painted to appear like they were captured Cuban planes. That evening the Cuban government tabled a motion to the United Nations, accusing the United States of being behind the attacks. Consequently a series of airfield attacks planned for the early hours of the 17 April were cancelled by Kennedy.
The amphibious assault went ahead as planned but quickly began to go wrong. The exiles from Brigade 2506 were pinned on the beach by a counterattack from the Cuban Army and assorted militiamen, leading to 114 exile deaths and the capture of over a thousand others. In the aftermath, Cuba developed even closer links with the USSR that led to the Cuban Missile Crisis the following year.