In the case of Kennebec Railroad v. Portland Railroad, the Supreme Court was asked to decide whether a railroad company had the right to build a bridge over a navigable river without the permission of the state legislature. The Kennebec Railroad Company had built a bridge over the Kennebec River in Maine without obtaining the necessary permission from the state legislature. The Portland Railroad Company, which operated a competing line, argued that the bridge was a public nuisance and should be removed. The Supreme Court ruled in favor of the Kennebec Railroad Company, holding that the bridge was not a public nuisance and that the company had the right to build it without the permission of the state legislature. The Court reasoned that the bridge was not a public nuisance because it did not interfere with navigation on the river and that the company had the right to build it because it was a private enterprise. The Court also noted that the state legislature had not passed any laws prohibiting the construction of such bridges. The Court's decision in this case established the principle that private companies have the right to build bridges over navigable rivers without the permission of the state legislature, provided that the bridge does not interfere with navigation. This ruling has been cited in numerous cases since then, and it remains an important precedent in the area of private property rights.

In the dissenting opinion of Kennebec Railroad v. Portland Railroad, Justice Field argued that the majority had misinterpreted a Maine statute which granted rights to railroads in order to build and operate their lines. He believed that this interpretation was too broad and would lead to an unfair monopoly for one railroad over another. Furthermore, he argued that it was not within the power of Congress or any court to grant such exclusive privileges as those sought by the plaintiff in this case. He concluded by stating his belief that if Congress wanted these kinds of monopolies they should be explicitly stated in law rather than inferred from existing statutes.