Incoming and outgoing correspondence between Zabel and his family, colleagues in the literary world, and professional associates. Of particular interest are letters between longtime friends Horace Gregory and wife Marya Zaturenska which convey Zabel's and Gregory's literary tastes and relationships to fellow writers. Letters between Zabel and poet Louise Bogan portray a vibrant but volatile relationship in which Zabel acts as critic and mentor, and provide insight into Bogan's writing process and life. Letters between Zabel and his mother Barbara and sister Barbara provide detailed chronicles of his many travels in Europe and South America.