Most of Cotton Mather's Greek and Latin citations from the Classics of ancient history and literature can be accessed through the following websites:
Thesaurus Linguae Graecae (TLG): The TLG is a research center at the University of California, Irvine. The TLG has already collected and digitized most literary texts written in Greek from Homer to the fall of Byzantium in AD 1453. The web version currently provides access to 3,700 authors and 12,000 works, approximately 91 million words. The TLG Library is stored in a database, known as the Canon of Greek Authors and Works. The full Canon is open to the public.
Corpus Scriptorum Latinorum (CSL): A digital library of Latin literature, CSL furnishes the public with access to a large number of classical Latin text (free of charge). For a full listing and access,
For similar free access to the Classics of Latin literature,
Perseus Digital Library @Tufts University
Armarium Labyrinth: Labyrinth Latin Bookcase @Georgetown University