EEBO contains searchable text of almost every work printed in England, Ireland, Scotland, Wales and British North America, as well as works in English printed elsewhere between 1473 and 1700.
"[A] vast eighteenth-century library at your desktop—a fully text-searchable corpus of books, pamphlets and broadsides in all subjects printed between 1701 and 1800. It currently contains over 180,000 titles amounting to over 32 million fully-searchable pages."
Digital Primary Sources: Library & Archival Collections
Millions of searchable texts from a partnership of research libraries. The material out of copyright is available to read; material in copyright is searchable.
A large but incomplete selection of titles from the ongoing digitization of every extant non-English-language western European book published before 1700.