Final answer:
Cream, The Grateful Dead, and Jimi Hendrix are mentioned in the textbook chapter as symbols of 1960s American popular culture, reflecting the era's idealism and subsequent transition to a more disillusioned nation due to political and economic crises.
Step-by-step explanation:
In the context of the chapter, Cream, The Grateful Dead, and Jimi Hendrix are likely mentioned as part of the discussion on American popular culture and its reflection of political culture in the late 1960s and early 1970s. The chapter may touch on how these musical artists represented the idealism of the 1960s through their music and lifestyle. It also addresses the transition into a more skeptical and disillusioned America as a result of events like Vietnam, Watergate, economic challenges, and drug overdose deaths of cultural icons such as Jimi Hendrix in 1970. This illustrates the waning of the counterculture movement and the questioning of American progress.