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Searching for Digitized vs. Non-Digitized content

Items are considered "digitized" if they are accessible in an online format such as a digital image, a digitized audio or video file, an "e-book" or a web page. Note that not all texts in the Library's Catalog can be read online, nor have all the images in our various collections been converted to digital formats.

Non-Digitized content are physical items, of all formats, from the Library's Catalog and Collections that can only be accessed first hand at Library of Congress facilities.

Searching for Exact Words or Phrases

The Use of Operators

The operators AND, OR, and NOT are supported. The Boolean phrase should be enclosed in parenthesis.

The Use of Quotation Marks

If you are searching for an exact match, enclose your search in quotes. If you enclose your search in quotes you will only get results for the exact terms or phrase you entered in the exact order you entered them.

Examples of searching for an exact phrase:

  • "Civil War maps"
  • "Jackie Robinson"
  • "Declaration of Independence"
  • "ice cream"

You can also search for an exact phrase and a keyword as in the following examples:

  • "civil war" maps
  • "Abraham Lincoln" funeral
  • farm "dust bowl"


Searches are NOT case sensitive. A search for "thomas jefferson" will return the same results as a search for "Thomas Jefferson."

Using Common Numbering Systems in Your Search

ISBN (International Standard Book Number)

Omit all hyphens and spaces; there is no need to enclose your search in quotation marks.

Search supports both 10 and 13 digit ISBN numbers.


  • ISBN 0-553-37783-3 use 0553377833
  • ISBN 978-0-97526-433-0 use 9780975274330

ISSN (International Standard Serial Number)

Include hyphens, but do not enclose your search in quotation marks.

Example: 0190-8286

Reproduction numbers for images

To search on Library of Congress Reproduction Numbers for images enclose your search term in quotation marks.


  • "LC-DIG-ppmsca-26457"
  • "LC-DIG-fsa-8b29516"
  • "LC-USZ62-114744"