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Call Numbers

Learn how books are organized and labeled at Northwestern University Library

Reading a Library of Congress Call Number

HN59 .T39 2014

H   Social Sciences

HN  Social history and conditions, social problems and social reform

HN59  America (59 means specific region or country)

HN59 .T39   Taylor (author)

HN59 .T39 2014   2014 indicates that this edition was published in 2014

HN59 .T39 2014   The next America : boomers, millennials, and the looming generational showdown / Paul Taylor.

  • Books are arranged alphabetically. The first letter of a Library of Congress call number indicates the general class the call number falls within. In our example, the book is located under H, which is where books on social sciences are classed. If there is a second or third letter, these indicate a specific subclass. HN indicates social history and conditions, social problems and social reform.
  • Numbers follow the letters. The numbers define the subject of the book. The number 59 is referring to a book about a specific region or country in this case, America.
  • The Cutter Number is the next set of numbers. The Cutter Number indicates the author or title of the book. It is taken from a table matching names or titles to a set of numbers. In our example, .T39 reflects the first word of the author, Taylor.
  • The edition of a volume is the next part of the call number. The year of publication follows the Cutter number to indicate the edition. In our example, 2014 indicates that this edition was published in 2014.

Each LC call number begins with one to three letters and is followed by a series of numbers. LC call numbers are organized alphabetically, starting with the first letter on the left. They are subsequently organized numerically according to the numbers that follow.

HN59 . T39 2014 The next America : boomers, millennials, and the looming generational showdown / Paul Taylor.