The United States is steeped in rich history and continues to evolve today. In the United States Encyclopedias series, readers will learn about the history of the US government and how it operates, take a look at the challenges and accomplishments of each US president, explore the breathtaking US national parks, and discover the uniqueness of each US state. This encyclopedia set is sure to give readers all they need to know about the United States of America. Encyclopedias is an imprint of Abdo Reference, a division of ABDO.