What is a rare book?
The answer to this question is more complicated than it may at first seem. The term "rare" is a moving target, changing meaning from country to country, institution to institution.
Here in the Rare Book & Special Collections Division at the Library of Congress, we generally consider an item to be rare if it was published prior to the year 1801. This date represents roughly the period when the Industrial Revolution transformed printing techniques, allowing for faster, cheaper production of books and other printed matter in larger quantities. Thus, materials printed after that time are less rare simply because more of them were available, and more of them remain.
Other factors can contribute to an item's "rarity" including its provenance. If an item has an interesting or important association with a famous person or group, it can also be considered "rare" regardless of the date of publication.
Additional Ways to Contact Us
Send written correspondence to:
Rare Book and Special Collections Division
Library of Congress
101 Independence Ave. SE
Washington, D.C. 20540-4740