What is a frontier? What are the frontiers of the future? What frontiers are being explored today? These and other questions are presented in this series on frontiers that helps make this concept come alive to all students. In Frontiers Book 2: Geography, Explorers, and Literature, students will discover the transcontinental railroad, the discoveries of Lewis and Clark, the mission to Mars, political cartoons, freedom of speech, and book bans. Other books in the Frontiers series include Frontiers Book 1: Pioneers, Genetics, and Energy and Frontiers Book 3: Geology, Astronomy, and Environment. Each book contains detailed lesson plans, reproducible activity sheets, and assessment tools. This curriculum unit makes use of the following great children"s literature books: If the World Were a Village by David J. Smith;Dragon"s Gate by Laurence Yep; andMaterial World: A Global Family Portrait by Peter Menzel (optional).