Library of Congress - Most people have heard of the Library of Congress, but few realize the amount of information it offers online. The American Memory Collection contains a wealth of materials on American history including thousands of photos, maps, documents, and even sheet music. In addition, the site offers online exhibits, and if you can't find what you're looking for there is online resource to ask a librarian. For anyone interested in American history, the Library of Congress is an invaluable resource that can provide you with a wealth of information not available anywhere else.