The establishment of a socialist system in Cuba led to the fleeing of many hundreds of thousands of upper- and middle-class Cubans to the United States and other countries since Castro's rise to power. By 1961, thousands of Cubans had fled Cuba for the United States. On 22 March of that year, an exile council was formed. The council planned to defeat the Communist regime and form a provisional government with José Miró Cardona, a noted leader in the civil opposition against Batista, to serve as temporary president until elections could be held.