EEBO Early English Books Online
Use the advanced search and limit the "Country of Origina" to "USA." EEBO contains over 100,000 books published in English since 1475. Based on Pollard & Redgrave's "Short Title Catalogue (1475-1640)" and Wing's "Short-Title Catalogue (1641-1700)," plus revised editions and supplements. Subjects covered include English literature, history, philosophy, linguistics, theology, music, fine arts, education, math, and science. Update: Texts continue to be added to the online version as they are scanned from the microfilm.