How to Cite Sources in Chicago Style
Overview
Chicago Style is the standard for history and humanities papers. This guide focuses on the Notes and Bibliography system, which uses footnotes to credit sources within the text and a bibliography to list them at the end. You will learn to format footnotes, create shortened notes for repeat citations, and build a professional bibliography page.
Step 1: Determine your citation system
Before writing, confirm which Chicago system your instructor requires. The Notes and Bibliography system is preferred in the humanities (history, literature, and the arts). It uses superscript numbers in the text that correspond to footnotes at the bottom of the page. The Author-Date system is more common in the physical and social sciences, utilizing parenthetical citations (Author Year, Page) similar to APA style. This guide follows the Notes and Bibliography format, as it is the most distinct feature of Chicago Style.
Step 2: Insert footnotes in the text
Place a superscript number at the end of the sentence or clause containing the borrowed information. This number should appear after all punctuation marks, including periods and quotation marks. At the bottom of that same page, provide the full citation details for that source. The first line of the footnote should be indented, and the note should start with the corresponding number (not superscript) followed by a period and a space. Use commas to separate elements like the author, title, and publication data.
Example: Footnote formatting
Text excerpt: `The industrial revolution fundamentally altered urban landscapes.¹` Footnote format: `1. James Smith, The Urban Shift (Chicago: University Press, 2022), 45.`
Step 3: Use shortened notes for repeat citations
When you cite the same source a second or third time, do not write out the full citation again. Instead, use a shortened note. This typically includes the author's last name, a shortened version of the title (if it is longer than four words), and the page number. Note that the 17th edition of the Chicago Manual of Style discourages the use of "Ibid." in favor of these shortened notes to improve clarity for the reader. Shortened notes save space while maintaining easy reference for your audience.
Step 4: Format the bibliography page
Create a separate page at the end of your essay titled Bibliography. Center the title at the top. List all sources used in your paper in alphabetical order by the author's last name. Unlike footnotes, bibliography entries use hanging indents (the first line is flush left, and subsequent lines are indented) and separate elements with periods rather than commas. If a source has no author, alphabetize it by the first word of the title. Double-space the entire page, but do not add extra spaces between individual entries.
Example: Bibliography entry
Book entry: `Smith, James. The Urban Shift. Chicago: University Press, 2022.` Journal article entry: `Doe, Jane. "City Planning in the 19th Century." Journal of History 12, no. 4 (2021): 112-130. https://doi.org/10.1017/s002.`
Common mistakes to avoid
Avoid these frequent errors when citing in Chicago Style:
- Incorrect footnote placement: Never place the superscript number before a period or inside a comma. It must always follow the punctuation.
- Mixing systems: Do not combine the Notes and Bibliography system with Author-Date parenthetical citations in the same paper.
- Using commas in the bibliography: Remember that bibliographies use periods to separate the author, title, and publisher, while footnotes use commas.
- Forgetting page numbers: Always include specific page numbers in footnotes for direct quotes or specific ideas, even if they are omitted in the final bibliography entry.
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