Google Book Search is Google's digitization project. The format is a scanned copy. 26 volumes were digitized.
HathiTrust Digital Library is a digital preservation repository and highly functional access platform. It provides long-term preservation and access services for public domain and in copyright content from a variety of sources, including Google, the Internet Archive, Microsoft, and in-house partner institution initiatives. 40 volumes were digitized.
Internet Archive Texts Collection is a "collection is open to the community for the contribution of any type of text," many were scanned by Microsoft's "Live Search Books" during 2006-2008. Multiple formats are provided. 35 volumes were digitized.
University of Michigan Digital Library. The format is a scanned copy. 40 volumes were digitized. It was done for the "Making of America" digital collection.
