Final answer:
The 2010 United States Census data indicates that about 80% of Americans lived in a metropolitan area, highlighting the urbanization trend.
Step-by-step explanation:
According to data from the 2010 United States Census, the percentage of Americans that lived in a metropolitan area is approximately 80%. Urbanization has been a consistent trend, particularly since the 1950s, marking a significant shift from rural to urban living in America. As economies develop, an increased proportion of the population moves to metropolitan areas, which include cities and their surrounding suburbs.