50 States, 5,000 FactsBy: National Geographic Series: 5,000 Ideas From the team that created the national bestseller 50 States, 5,000 Ideas, this engaging treasure trove of trivia boasts interesting tidbits about the United States and is perfect for trivia buffs, history lovers, and fact finders. Did you know that there is a floating post office in Michigan? Or that a library book checked out by George Washington was returned to a New York City library 221 years late?