This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book discusses Inquiry-Based Lessons in US History: Decoding the Past, is the culmination of those professional development sessions, planning and coaching conferences with teachers, and site visits to help implement inquiry-based, primary source lessons with students. It provides the middle and high school students, with the idea that world history is taught as a stand-alone course in those grades, and lesson plan supplements in the middle and high school courses must reach a number of audiences and cover a wide range of time periods and places. The book begins with a short section detailing the historical context to provide teachers with a reference point for the primary source materials in the lesson plans, followed by the National Center for History in the Schools world history standards and Common Core Literacy in History/Social Studies standards targeted in the lessons.