This collection contains the manuscripts, correspondence, drawings, and other papers of twentieth-century Guatemalan author Augusto Monterroso, who spent most of his life as a writer in Mexico.

Consists of research material of American educator and historian Harold Ruland relating to his study of Sebastian Munster (1489-1552) and the history of cosmography and early cartography.

Consists of correspondence, manuscripts, and printed material relating to the Fitzgerald biography The Far Side of Paradise (1951) by the literary critic, editor, biographer, author, and educator Arthur Mizener.

Consists of articles, correspondence, notes, miscellaneous material, and printed matter of William McElwee Miller, a Presbyterian clergyman and a missionary in Iran from 1919 to 1962.

Consists of select correspondence, dating from 1946 to 2011, of art historian Charles W. Millard (1932-2017) with artists such as Sir Anthony Caro, Helen Frankenthaler, Carl Chiarenza, Mark Hewitt, Nick George, Jules Olitski, and others.

Consists of an open collection of manuscript material related to print collections of Leonard L. Milberg (Princeton Class of 1953): Leonard L. Milberg Collection of American Poetry, Leonard L. Milberg Irish Theater Collection, and the Leonard L. Milberg Collection of Jewish-American Writers.

Helmut Meyer was a German-born American citizen who fought for the United States in World War II and founded the Helmut Meyer Literary Agency in New York City. The collection contains files from the Helmut Meyer Literary Agency, propaganda from both the Allies and the Axis from World War II, manuscripts of Meyer's own work, and correspondence from friends and clients.

The Gordon Merrick Papers consist primarily of drafts of the manuscripts of Merrick's novels, written over a thirty-nine year period, from the late 1940s ( The Strumpet Wind, 1947) to the mid-1980s ( Measure of Madness, 1986). Also present is his business and financial correspondence with agents, publishers, and banks over a twenty-one year period, from 1967 until his death in 1988. In addition there is a clipping file which dates back to Merrick's first experiences as an actor in the 1930s, as well as photographs taken for publicity as well as for Merrick's personal collection.

Consists of 167 letters by American poet William Meredith to his intimate friend Robert Drew from 1949 to 1972, postmarked Princeton, N.J., New London, Conn., and other places.

Consists, for the most part, of letters to American poet William Meredith (Princeton Class of 1940) from American authors, most of whom have been associated with Princeton.

Livingston T. Merchant was a diplomat and high-ranking government official. This collection consists of Merchant's papers, including correspondence, articles, notes, speeches, statements, interviews, clippings, printed matter, and personal papers.

Arthur Mendel was a prominent music scholar in the twentieth century and a professor at Princeton University. The collection contains correspondence with professional colleagues, course notes, musical notes, scrapbooks, and clippings. There is also additional unprocessed material from Mendel's time at Princeton.

Consists of 110 letters by influential magazine editor and critic H. L. Mencken to David Warren Ryder, a San Francisco area journalist, written mainly from Baltimore and New York between the years 1922 and 1947.

Consists of autograph manuscript notes, notebooks, correspondence, and a copy of a legal document.

Horace and Thomas Meeker were father and son graduates of Princeton University. The papers document the University's admission processes circa 1925 and 1950.

Harold R. Medina was a well-known judge and active Princeton alumnus. These records document Judge Harold Medina's role as a trustee of Princeton University, a member of the Graduate Council, and a member of the advisory council for modern languages and literatures.

Harold Raymond Medina (1888-1990) was a noted jurist, Princeton alumnus, and creator of a New York State Bar preparation course. This collection includes legal records, personal and professional correspondence, photographs, audio recordings, and teaching materials; in aggregate, they offer a substantial record of Medina's life and work.

Consists of papers of Kenneth McKenzie (1870-1949), a former professor of Romance languages at Princeton, relating to fables.

George Stanley McGovern was a Congressman (1957-1961), a U.S. Senator (1963-1981), and a Democratic presidential nominee known for his strong liberal stance, particularly during the Vietnam War. This collection contains legislation files, campaign materials, correspondence, speech texts, schedules and invitations, travel files, patronage files, subject files, photographs, and audiovisual materials documenting McGovern's activities in the House of Representatives and in the U.S. Senate, as well as his time as Director of Food for Peace.

The collection consists of the editorial files and personal papers of Margaret K. McElderry. Publisher files include editorial correspondence, legal documents, and production files related to specific authors and publications.

Consists of manuscripts, correspondence, drawings, and other material of the author, journalist, and Princeton graduate (Class of 1905) Samuel Duff McCoy (1882-1964).

Consists of the selected writings and correspondence of American educator and writer, Grace Latimer Jones McClure. Materials primarily relate to her unpublished book, A Clippership Honeymoon, which centers around the diaries of Malvina "Mallie" McClure, the wife of a mid-19th century New England sea captain.

Consists of writings, diaries, correspondence, organizational records, clippings, and other personal papers of Irish poet Thomas McCarthy, including drafts of poetry, fiction, and nonfiction works from the 1970s through the 2010s; extensive diaries and notebooks on personal and literary topics; files related to his work with Cork 2005, the Triskel Arts Centre, and other cultural and arts organizations in Ireland; transcriptions and recordings of interviews and events; and teaching materials.

The McCarter Theatre was conceived as a permanent home for the Princeton University Triangle Club. McCarter began as a booking theater but ultimately moved into producing its own performances. The McCarter Theatre records document the history of the McCarter Theatre, including administration, performances and productions, and the building itself.

George McAneny served in numerous positions in the government of New York City, including president of the Borough of Manhattan (1910-1913), president of the Board of Aldermen (1914-1916), and chairman of the State Transit Commission (1921). This collection consists of lectures, reports, correspondence, committee and association files, clippings, scrapbooks, and photographs, all of which reflect his special interests in regional and city planning, zoning, city and state transit, and city financing.

Consists of writings, notebooks, correspondence, files from Time magazine, subject files, legal and financial correspondence, photographs, and printed material of T. S. Matthews, an author and editor of Time magazine.

H. Freeman Matthews, Jr., son of H. Freeman Matthews, was a career Foreign Service officer, serving with the State Department from 1952 to 1991. The collection consists of materials documenting Matthews, Jr.'s service with the State Department, in particular, his time as Deputy Chief of Mission in Cairo from 1976 to 1980.

Harrison Freeman Matthews Sr. (1899-1986) was a U.S. diplomat and career ambassador. This collection consists of correspondence, a draft of his memoirs, photographs, clippings, films and miscellaneous papers. It includes correspondence with Elizabeth Luke Matthews and a diary she kept during a visit to her husband in Vichy, France in 1940-42.

Dean Mathey (d. 1972), Class of 1912, was a member of the Board of Trustees and an ardent supporter of the University. The collection documents Mathey's familial relationships, service to Princeton, tennis career and other activities from his undergraduate days to the end of his life.

Consists of letters and other material related to Sylvia Beach (1887-1962), the American proprietress of the Paris bookshop Shakespeare and Company, collected by Jackson Mathews (1907?-1978).

Consists of selected material by and about the American poet Edgar Lee Masters, collected by Gertrude Claytor, a friend and fellow poet.

Alpheus T. Mason taught in the Dept. of Politics at Princeton University beginning in 1925 and authored a number of legal works as well as biographies of Supreme Court justices Harlan Fiske Stone and Louis D. Brandeis. This collection consists of papers of Mason, including material relating Stone, Brandeis and Woodrow Wilson.

José Martínez Sotomayor was a Mexican lawyer, judge, and writer who published novels, short stories, and nonfiction. His personal papers includes correspondence and autograph and typescript manuscripts of three of Martínez Sotomayor's books.

Consists of two distinct groups of papers of author Robert Bernard Martin: material relating to his scholarly research and writings on the English novelist and clergyman Charles Kingsley and manuscripts of eight of Martin's published novels and works of non-fiction.

Consists of scrapbooks of tearsheets and clippings, original artwork in pencil and in pen and ink, correspondence, financial documents, periodicals, permission agreements, and contracts spanning Henry Martin's career as a cartoonist and illustrator.

Anne Martindell was one of the first three women to serve in the New Jersey State Senate. After her four-year term ended in 1977, she served as director of the Office for Foreign Disaster Assistance, and was ambassador to New Zealand and Western Samoa for a two-year term. The papers document her career in politics and civil service, and also contain her unpublished memoirs and personal papers.

Consists of the papers of Allan Marquand, Princeton art professor, founder of the University's Department of Art and Archaeology, and first director of its Art Museum.

Julia Marlowe (1866-1950), who was also known as Sarah Frances Frost, was an American actress and Shakespearean performer. Her collection consists chiefly of letters to Ida Rissland Perscheid. Also included are photographs of both Marlowe and her husband, E. H. Sothern, articles by and about them, memorabilia, and scrapbooks of newspaper clippings.