Early English Books Online EEBO (1475-1700). Includes all known editions of separately published and collected editions of plays, including verse drama and closet drama, by Elizabethan, Jacobean, and Restoration playwrights as well as texts about theater, including the evils of attending theater.
Eighteenth Century Collections Online ECCO Includes 18th-century editions of plays by dramatists since the beginning of English theater, as well as books about the theater, memoirs of actors, etc..
Folger Digital Texts. "Meticulously accurate texts" of the plays and poems from editions in the Folger Shakespeare Library in Washington, D.C. Under a Creative Commons license, access is free as is downloading of the source code for non-profit projects.
An American Ballroom Companion: Dance Instructional Manuals Ca. 1490-1920. A collection of over two hundred social dance manuals at the Library of Congress.
American Variety Stage: Vaudeville and Popular Entertainment, 1870-1920. Included are 334 English- and Yiddish-language playscripts, 146 theater playbills and programs, 61 motion pictures, 10 sound recordings and 143 photographs and 29 memorabilia items documenting the life and career of Harry Houdini. Part of the American Memory project from the Library of Congress.
The New Deal Stage: Selections from the Federal Theatre Project 1935-1939. Includes over 13,000 images, including costume designs, photographs, posters and scripts from the Project's archive at the Library of Congress.