Some two months after the barbudos of the Sierra Maestra made their triumphant entry into Havana, on March 10, 1959, Princeton University extended a formal invitation to Fidel Castro Ruíz, the 32-year-old Premier of Cuba and leader of the Revolution, to address a Senior Conference of the American Civilization Program, led by Robert Palmer, the Dodge Professor of History. Dr. Castro, as he was politely referred to in University correspondence, was asked to speak on the theme of "The United States and the Revolutionary Spirit," on April 20, 1959.