Mao because they were relatively well educated, and he needed competent administrators to staff his future regime". Most of the Long Marchers and rural recruits from within the Communist bases were illiterate peasants. It was these more recent volunteers who were Mao's primary "target". A large number of the young volunteers congregated in Yan'an, the capital of Mao's Communist Party. By the time Mao Zedong started his drive to "condition" them, around 40,000 had arrived. Most were in their late teens and early twenties, had joined the CCP in territories controlled by the Nationalists, and later departed to Yan'an. They were excited at reaching what was called a "revolutionary Mecca." One young volunteer described his feeling: "At last we saw the heights of Yenan city. We were so excited we wept. We cheered from our truck ... We started to sing the "Internationale", and Russia's Motherland March.'" The Party's leadership, however, reflected the CCP's origins south of the Yangtze River, and was at best supplemented by the intellectuals who trekked out to Yan'an to join the Party during the war against Japan. The Yan'an Rectification Campaign was also directed towards the indoctrination of older Communist Party personnel. "The Party chose to re-emphasize its basic principles during this period, in an evident determination to maintain its Leninist foundations in the midst of all the changes brought about by the war-time shift to the united front." The Yan'an Rectification Campaign improved the discipline, education, and organization of the membership of the CCP. Having lost many veterans before and during the Long March, the Communists found new sources of recruits among urban youth, students, and intellectuals. Alienated from the Nationalist government and doubting its resolve in resisting the Japanese, many new CCP volunteers were drawn by communist propaganda that portrayed the CCP as "the saviors of the nation", promising democracy and liberal reforms. As a result, hundreds of thousands of students, teachers, artists, writers, and journalists poured into Yan'an, seeking a revolutionary career. In Marxist classification these new recruits were of petit bourgeois origin. Their enthusiasm and various sorts of expertise were useful for the revolution, but only after they had undergone a thorough political reeducation and ideological reform. The process of indoctrination extended even to the cadres who had survived the Long March and "proven their revolutionary credibility." All Party members were reeducated with the newly established "Mao Zedong Thought" in order