In what ways was the economy of the United States changing?

you can explain the concepts in more detail if you want a longer answer

Explanation:

From the era of Reconstruction to the end of the 19th century, the United States underwent an economic transformation marked by the maturing of the industrial economy, the rapid expansion of big business, the development of large-scale agriculture, and the rise of national labor unions and industrial conflict.

(hey can u mark me as brainliest if you liked this answer)

these civilizations were located around fertile rivers, where they could produce an abundance of crops