Final answer:
Laissez-faire economics, predatory tactics, and the lack of government regulation led to the railroads having a monopoly.
Step-by-step explanation:
The sequence of events and policies that led to the railroads having a monopoly can be attributed to a combination of factors, including laissez-faire economics, predatory tactics, and the lack of government regulation. During the late 1800s, the United States government adopted a laissez-faire economic policy, which allowed businesses, including the railroads, to operate without much government intervention. This policy resulted in competing companies merging and consolidating their power, eventually leading to monopolies in the railroad industry. These monopolies engaged in predatory tactics, such as charging different rates and exploiting farmers, which caused the government to pass laws and regulations to break up the monopolies and protect consumer interests.