We've never had trouble getting One to read history books or listen to them being read. In fact, we fought him for a while on fiction, because he couldn't be bothered with something that "wasn't real". Here is a list of boy-friendly history books, just right for the 6-10 year old crew:
The grandaddy of them all: The Kingfisher History Encyclopedia. We read a page of this a day the year we home schooled; now it hangs around the house for reference. One has actually read up to the Great Depression on his own. Yes, I'm kind of frightened by that - funny you asked.
The You Wouldn't Want to be a ... series is great. One read them all in first grade and occasionally reads them aloud to Two, who loves the pictures.
Another great series are the National Geographic biographies. We have Galileo, Eleanor of Aquitaine, Alexander the Great and Saladin. These are read-alouds for younger boys and read-alones for One - for at least a year now. I had to con One into reading Eleanor, but once he did he loved her. That's because he's used to steely-eyed tough chicks as role models - I'm his mom, after all.
More great biographies are in the Biographies from Ancient Civilizations series. We have a stack, and One has been reading them himself since 1st grade.
Jean Fritz has written a number of good short books on early American history. One has read some of the Revolutionary War titles, including Where was Patrick Henry on the 29th of May?
One's newest biography obsession are the Sterling Point books. He's read Alexander the Great (a favorite hero of One's), Lawrence of Arabia, and has John Paul Jones, Admiral Byrd, Teddy Roosevelt and Ben Franklin waiting on his shelf.
The last 2 read-alones I can really recommend are The Emperor's Silent Army (read and re-read a dozen times) and The World Made New. The former has wonderful pictures of the clay statues, and the latter is a nice 50 page summary of the Age of Exploration.
For read-alouds, you can't go wrong with Rosemary Sutcliff's interpretations of the Iliad and the Odyssey: Black Ships before Troy and The Wanderings of Odysseus. I have a feeling One will pick these up himself someday soon - he was spellbound when his dad read them to him a year or more ago. And if you're into mythology after reading those, don't forget the D'Aulaire's wonderful books, Greek Myths and Norse Myths. Definitely things boys can sink their teeth into. Best to read aloud the first time through, to get all the names right if nothing else.
Finally, a little dry but great for covering a lot of ground in a relatively short time, are re-prints of some older books by Yesterday's Classics: Famous Men of Greece, Famous Men of Rome, and Famous Men of the Middle Ages. A chapter for each historical figure, they help to round out something like Kingfisher and get boys acquainted with some of the famous names they will study in more depth later on.
The goal of all this history - besides satisfying One's great love of the subject - is that spelled out in The Well-Trained Mind: the acquisition of facts. This task is central to the "grammar" or first stage of a classical education. And frankly, it works. Just think of all the boys you know who can name every member of a baseball or football team and even give you stats on the players. Why not translate that desire to collect facts into something a little more useful?