Documenting the sources you use in your senior essay is a key part of the research and writing process. Complete and accurate citations to the books, journal articles, primary sources, and other items you use will allow readers to verify your sources and explore them further if they'd like to learn more about the issues you've raised.
In the field of history, the standard citation style is the Chicago Style, and you will want to consult it to find the proper format for citing sources in your footnotes as well as at the end of your paper in your bibliography. Here are the main links for referring to the Chicago Manual of Style:
In addition, the Purdue OWL (Online Writing Lab) offers a helpful overview of the Chicago Manual of Style.
You may already have a software program or a system for keeping track of your sources, but, if not, you will want to think about what way of organizing your research will work best for you this coming year. The Yale University Library has licenses to certain citation management tools, and there are also free tools on the web for managing your citations. Probably the two most useful tools to consider are:
For more information and an overview of several of the resources that are available, see our citation management guide (but keep in mind the link there goes to an earlier version of Refworks that is no longer supported or used for new accounts, so you will want to use the link above for RefWorks).