Chicago Manual of Style is a formatting and citation style used primarily by history and some humanities disciplines.
It relies on standards created by the University of Chicago Press and published as:
Chicago Style allows for multiple ways to cite resources, but the two favored at HCC are: footnotes (without a bibliography) and author-date references (with a bibliography).
There is no bibliography at the end of a paper; instead, every time that a resource is referenced within the body of the text, a footnote is used. This does not mean that a footnote number exclusively refers to a single resource; instead, the numbers in the footnotes only attribute the sequence with which resources were referenced within the body of the text (e.g., one could have only two resources but 100 footnote citations that merely alternated between the two resources).
Parenthetical and in-text citations (containing authors' last names, publication years, and page numbers) with a bibliography at the end of the paper.
If your professor requested both footnotes and a bibliography, this means you will have to include all of your citations in two differing formats. Use the footnotes guide for your note citations, and use the author-date references guide for your bibliography citations. You can also use the additional Chicago Style resources linked to below.
This is called the notes and bibliography system of the Chicago Manual of Style. It is the most common practice for citing with Chicago, but it is not practiced as commonly at HCC as the bibliography citations provide only redundant information without supplementary annotations.