Final answer:
U.S. job growth since the 1970s has mostly occurred in the service sector.
Step-by-step explanation:
The U.S. job growth since the 1970s has mostly occurred in the service sector. According to the U.S. Department of Labor's Bureau of Labor Statistics, jobs in services have increased dramatically in the last few decades. Jobs in government have increased modestly, and jobs in manufacturing have declined. The service sector includes industries like entertainment, tourism, media, healthcare, financial and legal industries, and education.