The collection consists largely of handwritten and typed correspondence dating from the 1960s to the 1980s between Carlos Márquez-Sterling and family, friends, and exiled Cuban political figures. The collection also contains postcards; unedited book manuscripts; event invitations, announcements and programs; audiovisual materials; photographs and clippings.

Notable correspondents include past Latin American presidents José López Portillo (Mexico), Joaquín Balaguer (Dominican Republic) and Otilio Ulate (Costa Rica), as well as Cuban political personalities like Carlos Prío Socarrás, Fulgencio Batista Zaldívar, Rafael Guas Inclán and José Miró Cardona. Márquez-Sterling also corresponded with such distinguished journalists and literary figures as José Ignacio Rivero, Arturo Alfonso Roselló, Horacio Aguirre, Gastón Baquero and Octavio R. Costa.

The collection also highlights important correspondence and documents from Márquez-Sterling’s involvement in Cuban exile organizations such as the Movimiento Patriótico Cuba Libre, of which he was delegate general, and these groups’ interaction with international and American political figures, to wit, Ronald Reagan, former US ambassadors to Cuba Spruille Braden and Earl E.T. Smith, and Nicaraguan ambassador to the United States Guillermo Sevilla Sacasa.