Final answer:
The sexual counterrevolution in the United States began around the 1980s, marking a conservative shift in attitudes towards sexuality after the liberal 1960s and 1970s.
Step-by-step explanation:
The sexual counterrevolution in the United States started to take form around the 1980s. This was a period marked by a cultural shift towards more conservative values regarding sexuality after the more permissive attitudes of the 1960s and 1970s. During the counterrevolution, there was a push back against the previous decades' liberalization of sexual norms, as seen in the rise of political and social movements that emphasized traditional family structures and conservative policies regarding sex education and reproductive rights.