"Four decades ago, on 30 April 1975, the final chapter of US engagement in the Vietnam conflict came to a close when Saigon fell to the communists of North Vietnam. In recognition of the dedication and perseverance of Agency personnel who stayed to the very end, and for our Vietnamese friends who did not make it out in time, CSI [Center for the Study of Intelligence] has compiled the statements of key Saigon Station and Agency employees involved in the US Embassy evacuation, including Saigon Chief of Station (COS) Thomas Polgar and his deputy (DCOS) Conrad LaGueux, Directorate of Operations (DO) Far East Division Chief Theodore Shackley, and Chief of Vietnam Operations Joseph Lazarsky.a Also included is an interview with a longtime DO careerist, who was on the ground during the evacuation. Polgar and LaGueux were among the last to be evacuated on 30 April 1975. CIA analysts were pessimistic about the likelihood of success in Vietnam--especially during 1964 and 1965, the months leading up to and including the Johnson administration's substantial escalation of US military forces in South Vietnam."
Central Intelligence Agency: https://www.cia.gov/index.html