The growth of industries and urban population was the major change, beginning in the late 1790's/ early 1800's using technological improvements and taking advantage of a large pool of immigrants which arises in the United States.
<u>Explanation:</u>
The need of labor in the industries for huge production attracted the attention of the rural people, it was an opportunity for the rural people to settle inside the cities and become urban. Around 1920, nearly the major parts of America was populated with urban communities.
Around the period 1870 and 1920, nearly 25 million immigrants entered the country. They came with an hope to take part in the industry labor and gain enough wages that wouldn't push them to poverty. Places like New York, Cleveland, St.Louis attracted a lot of immigrants as it was a place of opportunities and in fact the immigrants were eager to work.
It was not just an advantage for the rural and immigrants but as well as for the factories and industries, who utilized these people for better use and development of the cities.
