We have a book called "The American Story" which is a collection of 100 true tales from American history that are in chronological order and have illustrations to accompany each story (I'd probably place this as a late-elementary to middle school level book). I'm sure you could find it at Amazon or at most bookstores. Playing off the MTH idea, what about the MTH Research Guides. They are related to the regular books but are non-fiction and go more in depth. Another idea would maybe be the "If You Lived . . . " books. They have books on everything from the signing of the constitution, Colonial times, the Sioux Indians, George Washington, Abraham Lincoln, and traveling west in a covered wagon. There are also the American Girl series, which are fiction but have a non-fiction section in the back of each book. I'm not sure if these are the types of books you're looking for, though.
