Open to the copyright page (back of the title page): “Library of Congress Catalog Card Number: 63-12345”
Dashes and spaces don’t matter. Paste works too — it looks up automatically.
One tap copies title + author (or the ASIN) — paste into AbeBooks, Amazon, eBay, your spreadsheet.
Looking up a stack you’re getting rid of? No lookup needed to donate: every book goes in my covered 24/7 drop box on Edith Blvd NE, any condition, and a whole library gets free pickup across the Albuquerque metro. Questions? Text 505-250-3804.
Why an LCCN lookup?
Every used-book workflow runs on ISBNs — scan or ten-key the number, get the book. But books printed before 1967 have no ISBN. What most of them do have is a Library of Congress Catalog Card Number printed right on the copyright page (“Library of Congress Catalog Card Number: 63-12345”, used since 1898). This tool makes that number work like an ISBN: type it, get the title and author, copy, and paste into whatever marketplace or database you use.
- Sorting donations or an estate? Key the LCCN instead of typing long titles and misspelled authors.
- Listing pre-ISBN books? Copy “title + author” in one tap and search AbeBooks, Amazon, eBay, or WorldCat.
- Need the exact Amazon page? When the record carries an ISBN, the lookup derives the ASIN (for print books the ASIN is the ISBN‑10) and links straight to the listing — LCCN in, Amazon catalog page out.
- Is it collectible? If the book is in the NMLP first-edition reference, the result links straight to its points of issue.
Where the number hides
Open the book to the copyright page (the back of the title page). Look for “Library of Congress Catalog Card Number”, “L.C. catalog card No.”, or just “LCCN”. The classic form is a two-digit year, a dash, and up to six digits (63-12345). Some carry a small letter prefix (sa 64-9056); books cataloged after 2000 use a four-digit year (2013019509). Dashes and spaces don’t matter here — they are normalized.
Where the answers come from
Lookups check the NMLP open first-edition reference first (instant), then public Library of Congress–derived records and Open Library. It’s an identification tool: it tells you what the book is, never what it’s worth. No account, no tracking, free forever — run a whole stack through it.
Checking whether a book is a first printing? Use the First Edition Checker — it reads copyright pages, decodes number lines, and now accepts Amazon links and ISBNs too.
Questions
What is an LCCN?
The Library of Congress Catalog Card Number is a unique identifier the Library of Congress has assigned to cataloged books since 1898. Publishers print it on the copyright page, which makes it the best machine-readable handle for books that predate ISBNs (pre-1967).
Where do I find the LCCN in a book?
On the copyright page (the reverse of the title page), usually as 'Library of Congress Catalog Card Number: 63-12345' or 'L.C. catalog card No.'. Older books may carry a lettered prefix like 'sa 64-9056'; post-2000 books use a four-digit year form like 2013019509.
The lookup found nothing — is the number wrong?
Maybe not. The serial part after the dash pads to six digits (63-945 becomes 63000945), so a mistyped digit is the most common cause. Some early, foreign-cataloged, or never-digitized records simply are not online; the result card links to the Library of Congress catalog for a manual check.