It happened in the 1800’s it allowed a lot more people to get paid more from their jobs resulting in a higher standard of living. This is where unions came in the picture, they wanted 8 hour work days and no child labor. The gilded age is known as a prosperous time for the nation but the government was very corrupt. There were corrupt industrialists, bankers and politicians who stole and benefited from the working class.
*The trans continental railroad made more people move west and created “robber barons”
*Since the government was corrupt muckrakers became a thing, the muckrakers exposed government corruption and such
This question goes a lot deeper, so if you want to know more just ask in the comments