CLEP History of the US II. Study for the CLEP History of the United States II Exam with 714 Flashcards. Here is a list of the categories and number of flashcards included in the program: Industrialization – 42 cards. Urbanization - 46 cards. Gilded age - 37 cards. Imperialism in America - 35 cards. Progressive Era - 67 cards. WWI - 39 cards. Roaring 20s - 42 cards.