Answer:
A. Many people moved from rural areas to urban centers.
Explanation:
In the last decades of the 19th century, a spatial structure emerged centered on a large and visible industrial pole: the Manufacturing belt (Northeast and Great Lakes). This area currently forms the largest urban-industrial concentration in the world, having as one of its characteristics the BOSWASH megalopolis (formed by the metropolitan areas of the Boston-Washington axis).
The population grew to about thirty million. They formed differentiated societies within the country. to the north and east came a powerful industrial and commercial bourgeoisie, along with a factory worker; to the south, the great aristocrats linked to large estates, monoculture, exportation and slavery predominated; In the Midwest, society was born from the pioneers, marked by the agricultural base and the livestock.
