Patrick K. O'Donnell is a bestselling, critically acclaimed military historian and the leading authority on American elite and special operations units. The author of fourteen books, including The Unvanquished, The Indispensables, The Unknowns, and Washington's Immortals, he is a senior fellow at Mount Vernon and has received numerous national awards. O'Donnell served as a combat historian with a Marine rifle platoon during the Battle of Fallujah and is a professional speaker who frequently lectures on America's conflicts, espionage, special operations, and the Revolutionary War. He has provided historical consulting for DreamWorks' award-winning miniseries Band of Brothers and for documentaries produced by the BBC, the History Channel, and Discovery. He lives in Ohio and Virginia.