Final answer:
John F. Kennedy's New Frontier exemplifies Gaddis's view, showcasing America's simultaneous prosperity and challenge during his presidency, marked by both ambitious social and technological progress and political crises like the Cuban Missile Crisis.
Step-by-step explanation:
John F. Kennedy's New Frontier is an example that aligns with Gaddis's interpretation of the period from 1945 to 1980. Kennedy's program focused on internal improvements and expansionist ideals, encompassing social, economic, and technological advancements. The New Frontier sought to address issues like poverty and racism, advocating for civil rights while also aiming to propel the United States to new levels of space exploration—epitomized by the moon landing in 1969.
On an international scale, the administration faced significant challenges, such as the Cuban Missile Crisis, which highlighted the volatile nature of Cold War politics. Nevertheless, the period was marked by a surge in national confidence and a belief in American innovation and leadership. Kennedy's New Frontier is emblematic of the duality Gaddis describes: a powerful, culturally dominant America, striving for progress amidst social and political upheaval.