Making of America
(MOA) is a digital library of primary sources in American social history primarily from the antebellum period through reconstruction. The collection is particularly strong in the subject areas of education, psychology, American history, sociology, religion, and science and technology. The book collection currently contains approximately 8,500 books with 19th century imprints.
You can either do a search, or see browse the information in a few places...
Can't tell if these browsing locations are comprehensive, or if there's overlap between them, but you can always go back to the main site and do searches if there's something in particular you are looking for.
This is a noble effort, and maybe one day soon collections like this will become commonplace.