What new social/economic class of people formed during the second industrial revolution in the us?

During the Second Industrial Revolution in the United States, the Treaty of Guadalupe-Hidalgo in 1848 was formed. It is the unprecedented urbanization and rapid territorial expansion.  It is secured Mexican cession of the Southwest to the United States. This expansion competes the visions free-soilers, immigrants from Europe, and Industrial capitalists.

hello,

  i would that it was because no matter how hard people worked everyone would be paid the same, witch it was a that the russian to rule.

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