The main database for finding journal articles in American history is America: History and Life:
However, there are several other databases you might wish to consult, especially if your topic has a second disciplinary angle (like Women's Studies):
The main tool for finding books in the library is the Library Catalog. Use the Library Catalog to find both ebooks and print books.
There are several major collections of ebooks. All the books in these collections should be represented by catalog records in the Library Catalog, but one obvious advantage to using these collections directly is that you can perform keyword searches in the full-text of the books that compose each collection: