This subseries, arranged alphabetically, consists of Oliver's correspondence with friends and colleagues, including well-known Latin American, European, and American novelists, poets, artists, and cultural figures. The largest number of letters are by Luis Saslavsky (126), followed by Victoria Ocampo (80+), Waldo Frank (40), and Eduardo Mallea (23). There is also a large amount of correspondence with individuals active in the organization World Council of Peace, in particular, the Colombian sociologist Diego Montaña Cuéllar, Colombian Jorge Zalamea, and Argentinian Alfredo Varela. Also of interest are the letters by Chilean peace activist Olga Poblete, British peace advocate Monica Felton, and director of the U.S. Section of the Women's International League for Peace and Freedom Mildred Scott Olmstead. Significant Latin American writers in the correspondence include Gabriela Mistral, Miguel Angel Asturias, Alfonso Reyes, J. C. Onetti, Gabriel García Márquez, and Mexicans Daniel Cosío Villegas and Jesús Silva Herzog. There is correspondence from numerous individuals of the Casa de las Américas in Havana, Cuba, and Roberto Fernández Retamar, in particular. Correspondence from other political and cultural figures in Argentina include Alfredo L. Palacios and Gregorio Bermann. There are numerous letters from the '20s and '30s of cultural interest-Conde Galeazzo Ciano (son-in-law of Benito Mussolini), German playwright Georg Kaiser, French theater directors Louis Jouvet and Lugné-Poe, architect Le Corbusier and philosopher Jacques Maritain. From the '40s and '50s, there are 11 letters by American dance executive Lincoln Kirstein and letters by American writers Howard Fast and Joseph Starobin. Undated, but probably from the '60s, are four letters by French author Simone de Beauvoir. The correspondence is also strong on Brazilian writers-there are 11 letters each (in Portuguese) by Jorge Amado and Vinícius de Moraes, spanning the years 1941-1975.

In this subseries, there is also correspondence which Oliver's family designated as María Rosa's "friends from childhood." Though filed separately by the individual's name, this group consists of Margarita Abella Caprile, Adelia de Acevedo, María Carmen M. de Achával, Manolo Bethbeder, Gilberto Brunelli, Coca Cano, C. Córdova Iturburu, Héctor Díaz Leguizamón, Luis de Elizalde, Kristina Estrada, Carla Filando, Susana Larguía, Robert Lignières, "Nenucha(?)", "María Luisa," Guillermo Martínez Guerrero, Marta Navarro Viola, Nicolás Olivari, "Renée," and Sara Tornquist de Shaw.

Also of interest in the General subseries is the correspondence of Tota Atucha [de Llavallol] (16 letters) who was a friend of both Victoria Ocampo and Oliver and lived in New York, N.Y. in the 1950s, and two poems written by Leónidas Barletta and Pablo Armando Fernández, filed with their correspondence. The poem by Barletta is about Oliver.