The papers of Shirley Jackson consist of diaries (1932-36), undated journals, correspondence, literary manuscripts, and miscellaneous papers.

There are approximately four hundred items in the Family Correspondence series which include letters Jackson received from her parents, Leslie H. and Geraldine B. Jackson, from 1944 through 1965 and photocopies of Shirley Jackson's letters to her parents from 1948 through 1965.

The General Correspondence series contains about 2,700 letters Jackson received from her literary agents, personal friends, and the general public, and includes letters from John Ciardi, Pascal Covici, and Louis Untermeyer. There are also a few outgoing letters written by Shirley Jackson in this group.

The greater part of the papers comprise a Literary Manuscripts series consisting of Jackson's short stories, articles, and books in the form of original manuscripts, typescripts, and printed galleys. Some of the scrapbooks relating to her published works contain correspondence as well.

Among the Miscellaneous series are Jackson's college notebooks for the years 1937-40 and many watercolors and drawings in pencil and ink.

The addition to the papers of Shirley Jackson covers the period from 1932 to 1970, with the bulk of the material dated between 1938 and 1965. Recognized as a master American short-story writer of the mid-twentieth century, Jackson specialized in creating tales with chilling and macabre insight into the psychological horror which she perceived to lie just beneath the surface of modern life. The addition contains material similar in nature to that which is located in the original portion and provides supplementary documentation for many of the same topics evident in that segment. Included in the addition is a diary kept by Jackson as a high-school student as well as correspondence with family and friends. Manuscripts and related papers reflecting the conception and development of many of her novels and short stories, which are highlighted in the original portion, are also included in the addition. Titles listed only in the addition include , , and .

The single most significant and fully developed file in the addition consists of a series of letters written to Jackson by her future husband, literary critic Stanley Edgar Hyman, while both were students at Syracuse University. Located in the Family Papers and containing sentiments that veer from the intellectually precocious to the sexually suggestive, the letters reflect the converging interests and emotional commitment of the couple and suggest both the endearing and passionate elements that would be characteristic of their relationship throughout their lives. Although the addition contains only scattered copies or drafts of letters written by Jackson, a complementary group of her original letters addressed to Hyman during the same time period, 1938-42, is located in the Stanley Hyman Papers in the Manuscript Division. The Family Papers also contain letters written to Jackson by her parents. Those written by her mother, Geraldine, suggest a relationship that influenced Jackson's personal outlook.

The addition also includes a Correspondence series which reflects many of the same personal and professional associations that exist in the main body of the collection. Files containing Jackson's professional correspondence with her agents and publishers, especially the publishing firm of Farrar, Straus and Young, and her literary agents, Brandt and Brandt and the Music Corporation of America, identify the editorial choices and corporate marketing decisions that contributed to the shaping and promotion of Jackson's literary career. Other correspondence documents the creation of Jackson's novels and stories, along with associated material in the Literary File under respective title headings.

Jackson met many of her most trusted friends and associates among a diverse group of young artists and writers while attending Syracuse University. Letters received from these correspondents and others of her contemporaries suggest the deep personal regard they held for Jackson, as both a professional writer whose stories were increasingly gaining critical acclaim and popular recognition and as a wife and mother who saw no incompatibility between her dual roles as artist and homemaker. The addition contains files of correspondence from several such friends, including Walter Bernstein, June Mirken Mintz, Frank Orenstein, Robert M. Strauss, and Jay Williams. Other correspondents of note include Jean Brockway, Elizabeth Batterham Burke, Carol Black Livaudais, Louis L. Scher, and Mary Shaw.

Jackson is best known for her unsettling tales of modern Gothic horror, in particular for her classic story, first published in the in 1948. She also wrote a number of humorous stories about contemporary domestic life. Based upon observations of her own family and largely sentimentalized for popular consumption, many were produced for general interest or women's magazines; two volumes, and , both centering on family life, were also published. The addition contains manuscript drafts, notes, and outlines relating to the development and execution of both types of Jackson's fiction. Located in the Literary File, the material enables the researcher to analyze the evolution of Jackson's form and style through the process of textual analysis and criticism.

Fan letters written to Jackson are contained in both the Correspondence series and under appropriate title headings in the Literary File. Inquiries from the public seeking clarification regarding the inspiration and interpretation of her work are quite common, especially for as successive generations of readers encountered this grisly tale anew.