Introduction to the Chicago Manual of Style
The Chicago Manual of Style (CMOS) is a comprehensive style guide established by the University of Chicago Press in 1906. Now in its 17th edition, it provides detailed guidelines for writing, editing, and publishing across disciplines. CMOS is widely used in academic publishing, especially in history and the humanities, and serves as a standard reference for writers seeking consistent formatting and citation practices.
Core Concepts of Chicago Style
Two Documentation Systems
Chicago offers two primary documentation systems:
- Notes-Bibliography System (NB): Primarily used in literature, history, and the arts
- Author-Date System: Commonly used in the physical, natural, and social sciences
General Principles
- Consistency throughout your document
- Clarity and precision in communication
- Proper attribution of sources
- Standardized formatting that aids readability
Chicago Citation Styles Overview
Notes-Bibliography System
Basic Structure
- Footnotes/Endnotes: Numbered references appearing at the bottom of the page or end of document
- Bibliography: Alphabetical list of all sources at the end of the document
Key Elements in Citations
| Element | Description | Example |
|---|---|---|
| Author Name | Full name, last name first in bibliography | Smith, John |
| Title | Book titles in italics, article titles in quotes | The History of Style |
| Publication Information | Publisher, date, page numbers | University of Chicago Press, 2020 |
| Access Information | For online sources: URL, DOI, access date | https://doi.org/10.1086/123456 |
Author-Date System
Basic Structure
- In-text Citations: Brief parenthetical references (Author Year, Page)
- Reference List: Alphabetical list of sources at the end of the document
Key Elements
| Element | In-text Format | Reference List Format |
|---|---|---|
| Basic Citation | (Author Year, Page) | Author, Year. Title. Publication details. |
| Multiple Authors | (Smith and Jones 2020, 25) | Smith, John, and Sarah Jones. 2020. Title… |
| No Author | (Title Year, Page) | Title. Year. Publication details. |
Step-by-Step Citation Process
Creating Footnotes/Endnotes (Notes-Bibliography)
- Insert a superscript number at the end of the sentence containing cited information
- At the bottom of the page (footnote) or end of chapter/document (endnote), include the full source information
- For subsequent citations of the same source, use shortened citations
- Include a bibliography at the end with full source information
Creating In-text Citations (Author-Date)
- Insert parenthetical reference immediately after cited information
- Include author’s last name, year of publication, and page number if quoting directly
- Include a reference list at the end with full source information
Citation Examples by Source Type
Books
Notes-Bibliography Format
First Footnote:
- John Smith, The Chicago Style Guide (Chicago: University of Chicago Press, 2020), 125-26.
Shortened Footnote: 2. Smith, Chicago Style Guide, 125-26.
Bibliography Entry: Smith, John. The Chicago Style Guide. Chicago: University of Chicago Press, 2020.
Author-Date Format
In-text Citation: (Smith 2020, 125-26)
Reference List Entry: Smith, John. 2020. The Chicago Style Guide. Chicago: University of Chicago Press.
Journal Articles
Notes-Bibliography Format
First Footnote:
- Sarah Jones, “The Evolution of Chicago Style,” Journal of Editorial Standards 45, no. 3 (2020): 223.
Bibliography Entry: Jones, Sarah. “The Evolution of Chicago Style.” Journal of Editorial Standards 45, no. 3 (2020): 220-238.
Author-Date Format
In-text Citation: (Jones 2020, 223)
Reference List Entry: Jones, Sarah. 2020. “The Evolution of Chicago Style.” Journal of Editorial Standards 45(3): 220-238.
Websites
Notes-Bibliography Format
First Footnote:
- “Chicago Style Overview,” University of Chicago Press, last modified May 16, 2022, https://www.chicagomanualofstyle.org/overview.html.
Bibliography Entry: University of Chicago Press. “Chicago Style Overview.” Last modified May 16, 2022. https://www.chicagomanualofstyle.org/overview.html.
Author-Date Format
In-text Citation: (University of Chicago Press 2022)
Reference List Entry: University of Chicago Press. 2022. “Chicago Style Overview.” Last modified May 16, 2022. https://www.chicagomanualofstyle.org/overview.html.
Chicago Formatting Guidelines
Document Formatting
- Margins: 1 inch on all sides
- Font: 12-point Times New Roman or similar readable font
- Spacing: Double-spaced text; single-spaced notes and bibliography
- Page Numbers: In the top right or bottom center of each page
- Title Page: Title, author, course/institution, date (centered 1/3 down the page)
Headings and Subheadings
| Level | Format |
|---|---|
| Chapter/Main Section | Centered, bold or plain, larger font |
| First Subheading | Centered, bold or italic |
| Second Subheading | Flush left, bold or italic |
| Third Subheading | Flush left, italic or bold |
| Fourth Subheading | Flush left, roman type with period, run into paragraph |
Punctuation and Typography
- Quotation Marks: Double quotes for quotations; single quotes for quotes within quotes
- Block Quotes: For quotations of 100+ words or 5+ lines, indented 0.5″ from left margin
- Em Dashes: No spaces around em dashes (word—word)
- En Dashes: For ranges (pp. 45–50)
- Serial Comma: Used in series of three or more items (red, white, and blue)
- Numbers: Spelled out for numbers up to one hundred or round multiples (e.g., two hundred)
Comparison: Chicago vs. Other Citation Styles
| Feature | Chicago (Notes-Bibliography) | Chicago (Author-Date) | MLA | APA |
|---|---|---|---|---|
| Primary Use | Humanities | Sciences | Literature, language | Social sciences |
| Citation Location | Footnotes/endnotes & bibliography | In-text parenthetical & reference list | In-text parenthetical & works cited | In-text parenthetical & references |
| Author Format | First name first (notes), Last name first (bibliography) | Last name first | Last name first | Last name first |
| Date Placement | After publisher | After author | At end of citation | After author |
| Title Format | Books: Italics; Articles: Quotes | Books: Italics; Articles: Quotes | Books: Italics; Articles: Quotes | Books: Italics; Articles: No quotes |
Common Chicago Style Challenges and Solutions
Challenge 1: Multiple Citations of the Same Source
Solution: Use shortened citations in footnotes after the first citation. In Author-Date, simply repeat the same parenthetical citation.
Challenge 2: Sources With Multiple Authors
Solution:
- Two or three authors: List all names in notes and bibliography
- Four or more authors: List first author followed by “et al.” in notes; list all authors in bibliography
Challenge 3: No Author
Solution: Use title in place of author name in both footnotes and bibliography
Challenge 4: Multiple Works by Same Author
Solution: In bibliography, replace author name with 3-em dash (———) after first entry; sort by publication date
Challenge 5: Electronic Sources Without Page Numbers
Solution: Use paragraph numbers, section headings, or chapter numbers when available
Best Practices and Tips
General Tips
- Maintain consistency throughout your document
- Create a style sheet to track specific formatting decisions
- Use citation management software (Zotero, EndNote, Mendeley)
- Consult the full Chicago Manual of Style for unusual cases
- Prioritize accuracy in quotes and citations
For Notes-Bibliography Users
- Use ibid. (in the same place) for consecutive references to the same source
- Place note numbers at the end of clauses or sentences
- Create full documentation for each source in bibliography, even if cited in notes
For Author-Date Users
- Include specific page numbers for direct quotations
- When citing multiple sources in one parenthetical, separate with semicolons
- Alphabetize reference list strictly by author last name
Resources for Further Learning
Official Resources
- The Chicago Manual of Style, 17th edition (University of Chicago Press, 2017)
- Chicago Manual of Style Online: www.chicagomanualofstyle.org
- Chicago-Style Citation Quick Guide: www.chicagomanualofstyle.org/tools_citationguide.html
Academic Support
- Purdue Online Writing Lab (OWL): owl.purdue.edu/owl/research_and_citation/chicago_manual_17th_edition
- University writing centers often provide Chicago style guides
Citation Tools
- Zotero (free): www.zotero.org
- EndNote: endnote.com
- Mendeley: www.mendeley.com
- Citation Machine: www.citationmachine.net/chicago
Remember: When in doubt about a specific citation situation, always consult the full Chicago Manual of Style, as it contains comprehensive guidelines for nearly every citation scenario.