Internet Archive is a non-profit library of millions of free books, movies, software, music, websites, and more.
Use the Wayback Machine to search over 349 billion archived web pages.
The Society of American Archivists offers lots of online resources for researchers working with archives. Some useful links:
The Special Collections at the University of Maryland Libraries is home to many primary source collections. Use this guide as a springboard for your research in the rich archives at the University of Maryland.
ArchiveGrid is a searchable index of over 5 million archival records, representing over 1000 different archival institutions. It also offers a map function that allows you to find archives near you.
Below you'll find a list of core primary source databases that offer access to full-text books, pamphlets, newspapers, and periodicals from the early modern period through the 19th century. The focus is English language materials published in the United States and Great Britain. For a more thorough guide to primary sources check out the British and US Primary Sources guide.