This doctoral dissertation analyzes the course of student activism at the University of Puerto Rico-Rio Piedras, the largest campus in Puerto Rico's public university system, during the first three decades of the island's current political status as an "Estado Libre Asociado" (Associated Free State/Commonwealth). It makes contributions in three lines of argument: university-state relations, connections between the student activism and the Puerto Rican independence movement, and student demographics and cultures. I found that the Puerto Rican state was committed to public higher education to advance socioeconomic mobility and instill civic virtue. Contradictions within the colonial "Estado Libre Asociado" are traceable through the University of Puerto Rico as it participated in the development of a cultural nationalist imaginary while having expansive US military presence through ROTC programs. I also explore interactions between student activism and pro-independence organizations off-campus, particularly in years known as the peak of the "Nueva Lucha por la Independencia" (New Struggle for Independence). I refrain from describing mid-twentieth century pro-independence student groups as a unified student movement, instead highlighting their diversity constant evolution. While the "Nueva Lucha" is known for its Left-leaning bent, this dissertation demonstrates that legacies of socially conservative Puerto Rican Nationalism exerted considerable influence over pro-independence student activism in Rio Piedras. Additionally, I explain the ways in which student demographics and cultures shaped waves of student protest in Rio Piedras. I examine how the campus became more socioeconomically and ideologically diverse during the mid-twentieth century due in part to "Estado Libre Asociado" initiatives and federal GI Bills. Increases in enrollment during this time resulted in the growth of annexationist (pro-statehood) student organizing in opposition to pro-independence groups in a campus where most of the student body did not belong to any political organization. Debates regarding university reform, anti-war activism, student-worker collaborations, and struggles in favor of expanded access to higher education shaped activist trajectories and contemporary discourses that represent students as leaders of social mobilization in Puerto Rico. Overall, this dissertation shows ways in which campus protest in Rio Piedras influenced the development of Puerto Rican political identities during the mid-twentieth century. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]