This unit covers the years 1898 to 1920. Progressivism is addressed in lessons on Jane Addams and Hull House, the trust busting efforts of President Theodore Roosevelt, the efforts of the organizers of the anti-lynching crusade, and the philosophical beliefs of the Social Gospel. Imperialism is addressed in lessons on the Panama Canal, Cuba and yellow journalism, the immigration and treatment of Japanese Americans, and the debate over Philippine intervention. Finally, the popular culture of the time period is examined in lessons on the growth of professional baseball and the writings of Mark Twain.

Students explore the Age of Imperialism using photographs, letters, diaries, newspaper headlines, political cartoons, broadsides, and other primary sources. Activities for each lesson incorporate one or more of these sources to give students the flavor of the era and to encourage independent, collaborative, and creative thinking, problem solving, and decision-making.