This collection consists primarily of the papers of William Seymour (1855-1933) that he created and collected throughout his lifelong involvement in the theater as an actor, stage manager, and director. The majority of Seymour's papers include correspondence with various prominent actors, directors, stage managers, and producers of the period, and numerous production-related materials, such as playscripts and promptbooks, notes, diaries, scene sketches, sheet music, ephemera and memorabilia among others. The scope is principally Seymour's connections with the New York, Boston, and New Orleans stage, though other cities are also represented. There is also some family correspondence; articles and essays that Seymour authored about his career and the theater more broadly; newspaper clippings; and a few personal documents.

Other Seymour and Davenport family members, particularly those who were prominent theater figures, such as Fanny Davenport (1850-1898), are also represented in the collection through correspondence, production materials, ephemera, and newspaper clippings.