Penny Candy is a great book. But can be hard to find. I went to two local "teacher supply" stores, and in both cases, the store managers sniffed, "We don't carry THOSE books." (The author, Richard Maybury, has written several books, called "Uncle Eric" books. They explain politics, history and economics in a clear, understandable manner. Get them all, if you can.)
Likewise, our county library doesn't carry THOSE books.