This is one of a four-volume series intended to improve students' (grade 6-adult) critical thinking through evaluation of conflicting viewpoints of United States history. Each lesson is a self-contained problem that can be integrated at any point in a corresponding history unit. The book represents both analytical and narrative history. Unit One offers a guide to critical thinking with exercises to develop differing types of skills. Unit Two has nine lessons dealing with the United States as a world power. Unit Three focuses seven lessons on the 1920s and the New Deal. Unit Four contains six lessons that examine foreign policy since 1945. Unit Five contains seven lessons about modern American society and politics. (EH)