Answer:
The American economy experienced, from the development of the Industrial Revolution and in particular after the War of 1812, a process of reconversion of its productive systems, which until then were eminently agrarian, to become predominantly industrial in the north of the country, based on the production of steel, the construction of ships, the elaboration of manufactures, and the industrialized exploitation of natural resources. This situation resulted in the development of a salaried social class, which went from working in their own fields to working in dependence for the owners of the industries, in exchange for a fixed monthly wage.
This meant a series of social changes in the nation, which had a decisive impact on the country's politics, economy, and culture. Thus, on the one hand, most of the wealth was transferred to the large cities of the north, while the main production centers were located there. This caused a huge migration by rural workers to the cities, which ended up determining the big city status of places like New York, Philadelphia, Pittsburg, Cleveland, Detroit or Boston, among other cities.
In addition, it motivated the creation of an urban middle class, which did not own the means of production but was not immersed in poverty, that worked in these industries.
On the other hand, this development caused the tensions between the north and south of the country, as it was a clash for two well differentiated lifestyles: urban and industrial in the north, against rural and agricultural in the south.
