Text as Data: Finding and Mining: Literature corpora

Documenting the American South Digital Collections: features multiple collections of digitized primary sources related to southern history, literature, and culture. Some collections offer plain-text downloads in their entirety: The Church in the Southern Black Community, First-Person Narratives of the American South, Library of Southern Literature, North American Slave Narratives.
 

HathiTrust Digital Library: a collaborative repository containing over 17.5 million titles (and counting) digitized by academic and research institutions across the U.S, Canada and Europe. Specializes in literature and U.S. Government document collections. Learn more in the HathiTrust section of this guide. Learn more in this guide's HathiTrust Digital Library and Research Center section. 
 

Project Gutenberg: an online library of 60,000 free digital books in the public domain that can be downloaded as text files for analysis.