- Under Dark Waters: Surviving the Titanic
- Under Drake's Flag
- Under Drake's Flag (Illustrated)
- Under Egyptian Palms; or, Three Bachelors' Journeys on the Nile
- Under Fate's Wing
- Under Fire: The Blitz Diaries of a Volunteer Ambulance Driver
- Under Fire: The Untold Story of the Attack in Benghazi
- Under Four Administrations: From Cleveland to Taft
- Under Full Sail
- Under God
- Under Himmler's Command
- Under Jerusalem
- Under Pressure
- Under Providence - Short History of How an Island Conquered a Sub-continent
- Under Six Flags: The Story of Texas
- Under söderns sol
- Under the Black Flag
- UNDER THE CANOPY
- Under the Crescent Moon with the XI Corps in the Civil War. Volume 2
- Under the Devil's Eye
- Under the Dragon
- Under The Gun
- Under the Influence
- Under the Influence, New Edition of the Unauthorized Story of the Anheuser-Busch Dynasty
- Under the Leader’s Cloak
- Under the Loving Care of the Fatherly Leader
- Under the Mountain Wall
- Under the Red Blanket
- Under the Red Sea Sun
- Under the Shadow
- Under the Southern Cross
- Under The Stretcher
- Under the Turk in Constantinople: A Record of Sir John Finch's Embassy, 1674-1681
- Undercover Girl
- Undercover Operator
- Undercover Washington
- Undercover: Operation Julie - The Inside Story
- Underestimated: Our Not So Peaceful Nuclear Future - Where We Are Headed, Worries, Going Ballistic, ...
- Underestimated: Our Not So Peaceful Nuclear Future, Second Edition - War Scenarios, China and Nuclea...
- Underestimating the Enemy: The Mistake That Starts Our Wars
- Underground
- Underground Factories in Germany Part 1
- Underground Factories in Germany Part 2
- Underground Philadelphia
- Underground Structures of the Cold War
- Underground to Palestine
- Underground Warfare, 1914–1918
- Underground Worlds
- Underground, Overground
- Underground, The Story of A People
- Undersea Warrior
- Understand Your Rights Because You're About to Lose Them!
- Understanding Primary Sources: Reconstruction
- Understanding Africa Book 1
- Understanding Ancient Fortifications
- Understanding Ancient Thought
- Understanding and Accounting for National Will in Strategies that Use Military Force: Case Studies o...
- Understanding and Managing North Korea's Nuclear Ambitions: DPRK Regime Survival, Use as Deterrence,...
- Understanding Carl von Clausewitz
- Understanding China [3rd Edition]