From left, Ernesto Che Guevara, Alfonso Zayas, Rogelio Acevedo, at 1964 reunion of combatants in Rebel Army column led by Guevara. “The Rebel Army was a political vanguard organization that was painstakingly selected and tested in battle,” Mary-Alice Waters writes. “As the revolutionary war advanced, these cadres became more educated and more politically homogeneous.”