This unit is a collection of lessons for teaching about cultural clashes. Based on primary sources, the unit contains teacher background materials and three lesson plans with student resources. These lessons deal with the United States between World War I and World War II. The United States emerged from World War I with seismic faults in its society, with clashes that would reverberate through the decade and beyond. A study of the contrast between modern urban and traditional rural society can help students grasp the era's great complexity and give them insights into different cultural attitudes that still exist in U.S. society. Using a variety of documents, plus cooperative and individual instructional activities that emphasize critical thinking, students examine the attitudes and strategies of people struggling with competing world views. Art, literature, and film also are used to illustrate key points. The unit is built on three objectives: (1) to identify social and economic changes that had been occurring in the United States since the late 19th century; (2) to identify reactions to the social and economic changes that had been occurring; and (3) to recognize that the emergence of new beliefs and attitudes produce tensions and conflicts in society. The first lesson plan, "Urban America in the Twenties," allows students to identify social and economic trends in the early 20th century, describe urban modernism in the 1920's, and reactions to it. The second lesson, "Rural Traditionalism in the Twenties," helps students describe rural traditionalism in the 1920's and reactions. The third lesson contains case studies. Contains three references. (Author/DK)