Overheard, from the observation platform above the Library of Congress main reading room:
Man: What do I need to get into the main reading room?
Guide: Curiosity.
Anyone can access the Library of Congress' reading room and more than 800 miles of books and resources, though you do need to apply for a reader's card. But that's available to anyone above high-school age, and even then you can use the library under certain circumstances.
"The primary function of the Library of Congress is to serve the Congress. In addition, the Library provides service to government agencies, other libraries, scholars, and the general public. "
It's a beautiful building with a lot to explore -- from the first map made and printed in the United States by an American, to displays on civil rights, due process and the documents which helped create our society.