Final answer:
The federal regulation of railroads in the late 19th century was achieved through the Interstate Commerce Act, which was passed by Congress in 1887.
Step-by-step explanation:
The subject of this question is Social Studies. This question relates to the regulation of railroads by the federal government in the late 19th century. The farmers, who were negatively affected by unfair practices of railroads, organized into The Grange and passed state laws known as the Granger Laws to protect their interests. However, in the Wabash, St. Louis & Pacific Company v. Illinois case, the Supreme Court ruled that only the federal government has the power to regulate railroads that engage in interstate commerce. As a result, Congress passed the Interstate Commerce Act in 1887 to establish federal regulation over railroads.