Library of Congress Washington, DC

Originally intended as a small reference library, the Library of Congress now contains the largest collection of books in the world, with 100 million items, including a Gutenberg Bible and first drafts of the Declaration of Independence and Lincoln's Gettysburg Address. The splendor of the magnificent Main Reading Room is worth the visit, but you should also browse the many excellent collections and exhibits in the library's three buildings. Its collections are available for research to adults 18 and older.