The papers in the Slack Family Collection have been artificially arranged and consist largely of correspondence collected by Susan Brune Randall and her daughter, Elizabeth Randall, to form an autograph collection spanning 1853-1928. The collection does not include any significant information regarding family or business interests.

The collection consists primarily of writings with additional family papers, photographs, and correspondence. The materials range in date from 1726 to 1972. The content is mostly related to the lives of Leolyn Louise Everett Spelman and Timothy Mather Spelman.

Stefan Einarsson (born 1897) was a professor of Scandinavian Philology at Johns Hopkins University. The collection consists of professional correspondence that spans the years 1942 to 1959.

Collection consists of draft of manuscript "Melos."

The collection includes the papers of John Barth (born 1930), American novelist and short-story writer, who is best-known for his contributions to postmodern literature. The collection spans the years 1930 to 2014 and consists of manuscripts, typescripts, and galley proofs of Barth’s writings; correspondence; reviews; and other professional papers.

Thomas Gresham Machen (born 1886) was an architect and book collector. The collection consists of clippings of Baltimore newspapers from 1859, correspondence from 1909 and 1945 relating to rare books, and an undated biographical sketch of Maryland colonial settler, Margaret Brent.

Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) was an American evolutionary biologist, geneticist, embryologist, and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries elucidating the role that the chromosome plays in heredity. This collection consists entirely of reprints of articles spanning 1889 to 1945.

Thomas F. Flannery was born in Carbondale, Pennsylvania in 1919. In 1957, he moved to Baltimore and became the first editorial cartoonist for The Evening Sun in 1957. Topics include: Baltimore and Maryland, sports and personages, national issues and world affairs in the late 1950s through the 1960s, including the Kennedy presidency, the war in Vietnam, and the Cold War.

The Trade Union Collection consists of printed material produced by unions and employers' associations dating from 1910-1964.

Victor Lowe (born 1907) was a professor of philosophy at The Johns Hopkins University, and the biographer of mathematician and philosopher, Alfred North Whitehead. This collection of papers largely relates to Lowe's research into the life of Whitehead and consists mainly of research notes, correspondence, and articles about Whitehead collected by Lowe. Included also are some personal papers which Lowe re-filed with these research files.

Victoria Lincoln was an American writer of fiction and journalistic articles born in 1904. The papers consist largely of drafts of her many articles, stories, poems, and novels. The collection spans 1833-1986, with the bulk of the material from 1925-1985.

William Julian Albert Bliss was born in Washington, DC in 1867 and was both a student and a professor at Johns Hopkins University. The collection consists of notebooks lecture notes, writings, and correspondence. The material spans 1892-1927, with the bulk spanning 1892-1894 and 1925-1927, and cover two periods of Bliss's career at Hopkins.

W.W. Holland was an industrial chemist and Hopkins researcher. Collection deals largely with Holland's work (1930-1934) on the Gyro process of cracking petroleum to produce gasoline. Includes research data, reports, correspondence, and printed material.

Walter Albert Patrick was a chemist whose research focused on devising a quick and cheap method of making silica gel, a desiccant, in large quantities. This collection consists of research, correspondence, typescripts, student papers, and publications from 1901-1968.

A collection of letters from contemporary literary figures and publishers.

William Bullock Clark was an American geologist born in Brattleboro, Vermont on December 15, 1860. The papers consist of correspondence, invoices, and a scrapbook spanning 1888-1925.

William (Bill) G. Fastie was a physicist born on December 6, 1916 in Baltimore, Maryland. The collection consists of materials relating to Fastie's professional work in optical physics and astrophysics and ranges in date from 1937-1995, with the bulk of the records concentrated in the 1960s-1980s.

Correspondence, publications, writings, photographs, and other personal papers of William Hand Browne, an early Johns Hopkins University librarian and English Professor, a life-long resident of the Baltimore area, and a Confederate sympathizer who helped promote the racism of the "Lost Cause" mythology in the years following the American Civil War.

William Keith Brooks (1848 – 1908) was an American zoologist who studied embryological development in invertebrates. The collection consists of research notes, reprints and drawings dating from 1880 to 1906.

William Paul Jones is presumed to have lived in Baltimore in the 1820s. The album (approximately 1820s) consists of messages and poetry written by Jones's friends when he was preparing to begin a life at sea.