Citations: Chicago Manual Style
Citations are a vital part of the research process. They allow the reader to locate items used as part of your research, lend credibility to your argumentation, and demonstrate your ability to participate in a scholarly dialogue. Proper citations also give credit to the original authors of the sources or ideas you are using. Without these citations, it is impossible to avoid plagiarism.
History as a discipline uses Chicago Manual Style:
Resources for Learning about Chicago Style
Quick Guides for Formatting Citations Using Chicago Style