How did the government finally try early examples successful? to control monopolies? were they

For the first question: the government finally try early examples and were successful because of the massive programs which were small initiatives to address problems. The government was optimistic and believed that Americans can do greater things.
For the second question: The government was able to control monopolies by implementing rules and regulations such as: putting a price capping by regulators, regulations of quality of service, merger policy, breaking up a monopoly, rate of return regulation, and investigation of abuse.