The Correspondence series, 1919-1991 (Bulk 1930-1969) (5.34 linear feet) consists of personal correspondence received, written, and collected by Luis Alberto Sánchez. This series is arranged in alphabetical order by name followed by chronological order. The majority of the correspondence are letters received by Luis Alberto Sánchez with a smaller number of letters written by Luis Alberto Sánchez. A very small number of items are letters written by correspondents to others and collected by Dr. Sánchez. These are retained in this series to reflect the original arrangement imposed by Don Henderson in consultation with Luis Alberto Sánchez. This series demonstrates Dr. Sánchez' relationships with APRA leadership and APRA members such as Víctor Raúl Haya de la Torre, Manuel Seoane, Nicanor Mujica, and Armando Villanueva del Campo. It also demonstrates Dr. Sánchez' relationships with the Peruvian government, foreign governments, and other prominent political figures throughout Latin America such as Juan José Arévalo, Fernando Belaúnde Terry, Rómulo Betancourt, and Juan Bosch. This series also demonstrates Dr. Sánchez' relationships with Latin American literary figures such as Alfredo González Prada, Alfonso Hernández Catá, José Carlos Mariátegui, Gabriela Mistral, Pablo Neruda, and César Vallejo as well as publishers in Peru and internationally.

Researchers should note that much of the correspondence with Apristas and other Latin American political figures is written under pseudonyms. After transferring his papers to Penn State University, Luis Alberto Sánchez worked directly with Don Henderson and Grace Pérez to properly identify these correspondents. The majority of the correspondence in this series was annotated and summarized in Literature and Politics in Latin America: An Annotated Calendar of the Luis Alberto Sanchez Correspondence, 1919-1980 and that the majority of the correspondence has been microfilmed. However, Pennsylvania State University received some of the correspondence after the book's publication and microfilming. Researchers should note that some folders include explanatory notes written by Luis Alberto Sánchez. In addition, during his 1974 visit, Luis Alberto Sánchez discussed three letters in a recording located in the Pennsylvania State University series.