Today’s episode reviews APUSH Units 5–7, a stretch where the United States is repeatedly tested. We begin with Manifest Destiny, the fight over slavery’s expansion, the Civil War, and Reconstruction’s unfinished struggle over freedom and equality. Then we move into the Gilded Age, where railroads, industry, immigration, cities, labor conflict, western expansion, and Jim Crow reshape American life. Finally, Unit 7 follows the rise of U.S. global power, Progressivism, World War I, the 1920s, the Great Depression, the New Deal, and World War II. The big theme: crisis expands federal power while exposing America’s contradictions.