History

Find it. Write it. Cite it. The Chicago Manual of Style Online is the venerable, time-tested guide to style, usage, and grammar in an accessible online format. It is the indispensable reference for writers, editors, proofreaders, indexers, copywriters, designers, and publishers, informing the editorial canon with sound, definitive advice.

From the Online Writing Lab (OWL), Purdue University.
Please note that although these resources reflect the most recent updates in the The Chicago Manual of Style (18th edition) concerning documentation practices, you can review a full list of updates concerning usage, technology, professional practice, etc. at The Chicago Manual of Style Online.