What is Chicago Style?

The Chicago Manual of Style (CMOS) 17th edition provides information and guidance regarding citations; the process of publishing; style and usage issues such as grammar, punctuation, and spelling; and indexes. CMOS has two distinct citation styles: notes-bibliography and author-date-references.  

Notes-bibliography style is used predominantly in the humanities - literature, history, and the arts. Notes are numbered, and can be footnotes appearing at the bottom of pages; endnotes appearing at the end of the work; or both.  Which type of notes used is flexible, based on the writer's needs. The bibliography is an organized list of all sources titled "Bibliography" and appears at the end of the paper. 

Author-date-references style is used predominantly in the physical, natural, and social sciences. This style is similar to notes-bibliography in most ways.  The main difference is the use of author-date in-text citations instead of notes.  These in-text citations consist of the source author's last name and the publication year in parentheses adjacent to the relevant text in the paper.  References are the same thing as a bibliography except for being titled "References." 

This guide offers basic rules for citing different types of sources using notes-bibliography style, as well as links to other CMOS resources.  Because Chicago style is detailed and quite flexible, to make this guide useful to our students it has been limited:

  • It is assumed that all sources will be listed in the bibliography (CMOS 14.19, 14.29).
  • Only footnotes in the shortened form are covered (CMOS 14.19, 14.29).