Final answer:
The decision in the Munn v. Illinois case did not succeed in checking the power of the railroads because it was overturned by a Supreme Court ruling. The court ruled that state laws regulating railroad rates were unconstitutional and only the federal government had the authority to regulate interstate commerce.
Step-by-step explanation:
The decision in the Munn v. Illinois case did not succeed in checking the power of the railroads because it was later overturned by a Supreme Court ruling. The court found that state laws regulating railroad rates were unconstitutional and that only the federal government had the authority to regulate interstate commerce, including railroads. This ruling weakened the ability of states to control the railroads and allowed the railroads to continue their monopolistic practices.