Final answer:
The 1960s in the United States are best characterized by increasing division and restlessness, marked by social, political, and cultural upheaval as citizens sought fundamental changes in the nation.
Step-by-step explanation:
The statement that best describes the United States during the 1960s is that the nation became more divided and restless as the decade progressed. This period was marked by a series of profound social, political, and cultural shifts. As the decade ushered in, Americans witnessed the promise of a better future during John F. Kennedy's presidency, but the optimism was shattered by events such as his assassination in 1963 and the intensification of the Vietnam War. Movements for civil rights, women's liberation, and other social reforms reflected a society in the throes of transformation, challenging the status quo and seeking to redefine American values.
During the early 1960s, the nation was already feeling a sense of restlessness, with economic recessions and setbacks in foreign policy impacting national morale. As the decade continued, the splintering of consensus became more apparent, as citizens from all walks of life and ethnic backgrounds strived to change the fabric of American society for a promise of equity. Despite previously unprecedented economic growth, many began to feel that the country needed fundamental changes, as shown through the actions of various activist groups and widespread cultural reassessment.