Why and how did the United States then implement the free market economic model of the

A free market economy is a market economy without government intervention.

Because the U.S. government had very little power when it was first formed, functioning only as a Department of Defense, it was impossible to meddle in economic affairs, so it was a free market economy.

By the time of the Civil War, the government's functions had expanded dramatically. Only gradually did it move away from a free market economy.

However, the real landmark was the event of the United States abandoning the dollar gold standard and adopting an anchorless currency. From then on, the government began to control the entire national and even world economy by adjusting the money supply, completely departing from the free market economy.