What were monopolies and trusts?

What were monopolies and trusts?
Monopolies and trusts were big businesses that had gained control over all other competition, therefore allowing themselves to regulate prices ( usually causing widespread debt on people who were reliant on their services ). An example of this is the railroad companies during the industrial revolution who could charge ludicrously per freight car of goods shipped to the farmers who were unable to get their goods out otherwise. These monopolies, or trusts, are now prevented by the government to keep them from hurting others as they did in the past.

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