In April 1960, the CIA began to recruit anti-Castro Cuban exiles in the Miami area. Until July 1960. For the increasing ranks of recruits, infantry training was carried out at a CIA-run base (code-named JMTrax) near Retalhuleu in the Sierra Madre on the Pacific coast of Guatemala. The exiled group named themselves Brigade 2506 (Brigada Asalto 2506).
In April 1960, FRD (Frente Revolucionario Democratico – Democratic Revolutionary Front) rebels were taken to Useppa Island, a private island off the coast of Florida, which was covertly leased by the CIA at the time. Once the rebels had arrived, they were greeted by instructors from U.S. Army special forces groups, members from the U.S. Air Force and Air National Guard and members of the CIA. The rebels were trained in amphibious assault tactics, guerrilla warfare, infantry and weapons training, unit tactics and land navigation.