"This chapter examines the history and development of Popular Cultural Action (Acción Cultural Popular, or ACPO), the multipronged project of Christian revitalization, local empowerment, and communitybased development whose radio education network, Radio Sutatenza, founded by a Colombian parish priest in 1947 to address rural adult illiteracy, became Latin America’s first Catholic radio network and the model for media-based rural education and community development programs in twenty-four countries throughout Latin America, Asia, and Africa. In nearly a half century of existence, ACPO published and distributed more than six million cartillas (illustrated instructional manuals) for its five-point “Fundamental Integral Education” (EFI) program, which included Alphabet, Numbers, Health, Economy and Work, and Practical Spirituality; distributed seventy-six million copies of the newspaper El Campesino; received and answered 1.2 million letters from rural listeners and readers; graduated twenty-three thousand Colombian and foreign radio auxiliaries and community leaders from its training institutes; logged 1.4 million hours of educational broadcasting; and pressed 690,000 records. By 1990, when ACPO was forced to shutter its press and record-cutting studios and sell off its 245 radio network and buildings, it had a presence in hundreds of rural parishes stretched across the length and breadth of Colombia, and its broadcasts and educational materials were frequently acknowledged as inspiration for many a professional of rural origin. ACPO was but one among many other Colombian projects inspired by Leo XIII’s Rerum novarum (1891) and spearheaded by both laypeople and clergy that emerged in the period before Vatican II to redress longstanding social, economic, and cultural inequalities made more acute in the first half of the twentieth century by the specter of totalitarianism, economic crisis, rural migration, urbanization, and incipient industrialization. This chapter traces the history of ACPO between 1947 and 1962. It grew from modest origins, conducting adult rural literacy work and basic community-centered development in three small, Central Andean settlements supported by local in-kind contributions and a small diocesan subsidy. Gradually, it would expand into a multimedia-based educational juggernaut with transnational influence, partners, and funding lauded by Pope Pius XII in a 1953 Vatican Radio broadcast heard throughout Latin America. By the late 1950s, ACPO was held as the model for Catholic-directed, radio-based rural education and community development. ACPO’s success and eventual influence beyond Colombia’s borders was partly the result of Catholic transnational activism occurring in the decades before Vatican II. Efforts to redress the excesses of unrestrained capitalism and to build a community based in papal encyclicals such as Rerum novarum or Quadragesimo anno, even when they stopped short of advocating the kind of structural, grassroots Christian base community approach embraced by Liberation theology, I suggest, laid the foundations for participatory and transformative forms of social action that emerged after Vatican II." (Pages 245-246)