For additional primary and secondary eighteenth-century sources, please see the 18th-Century Sources Guide.
N.B.: In the United States, most works published before 1923 are in the public domain, but finding full-text material after that date often requires looking for it in libraries, archives, or in subscription databases. To find full-length books published after 1923, search Tripod (for items in the Tri-College libraries) or WorldCat (for items in libraries around the United States and the world).
Below is a sample of the kinds of projects and sources for early-20th-century literature for which you might search: