This collection consists of personal papers of Caroline Newton (1893-1975), including manuscripts, typescripts, and notebooks containing her translations and other writings, correspondence, family papers, photographs, ephemera, printed materials, and writings of others. The writings are largely literary in nature and include unpublished manuscript translations of Johann Wolfgang von Goethe's Conversations with Eckermann and Wilhelm Meister's Apprenticeship and Travels, and a manuscript of The Letters of Thomas Mann to Caroline Newton (Princeton, N.J.: Privately published, 1971). Also present are Netwon's numerous writings and notes about Thomas Mann and other literary figures, as well as a smaller amount of notebooks and patient notes from her study and practice of psychoanalysis.

Newton's correspondence primarily pertains to Thomas Mann, publishing, and collecting, and her correspondents include W. H. Auden, Sigmund Freud, Sir Shane Leslie, Wilmarth S. Lewis, and others. Her correspondence with Katharina Hedwig Pringsheim Mann (also known as Katja or Katia, who was married to Thomas Mann) is particularly robust, spanning over one hundred letters across five decades. In addition, there is a collection of family papers about Leonard Jerome, Winston Churchill, and their families, which includes an unpublished manuscript, "The Life of Leonard Jerome of New York," and an essay, "Winston, a Cousinly Memory," both by Sir Shane Leslie. These family papers include original correspondence and photographs of both Jerome and Churchill. Also present are various personal ephemera and printed materials belonging to Newton, and a small selection of papers of others, which includes correspondence of Felix Dahn and Fritz Endres.