This research note discusses an emerging subfield of inquiry in the study of democratization in Latin America: a focus on the relationships between past human rights abuses and democratization processes. It outlines four sets of questions emerging around the themes of “historical memory” and “legacies of authoritarian rule.” The study then examines documentary collections of major human rights nongovernmental organizations (HRNGOs) in Argentina, Chile, and Uruguay. The purpose of this endeavor is to provide researchers interested in studying the four issues with specific information on documents produced and currently held by the HRNGOs in the Southern Cone. The essay examines seven HRNGOs in Chile, ten in Argentina, and four in Uruguay, and ends with practical hints for researchers who wish to use these resources.