In the case of Keokuk & Hamilton Bridge Company v. United States, 1922, the U.S Supreme Court ruled that a bridge company was not exempt from paying taxes on its income derived from tolls collected for crossing its bridge over navigable waters between two states. The court held that although Congress had granted the company permission to construct and maintain a bridge across the Mississippi River, it did not imply an exemption from federal taxation. The decision clarified that such exemptions must be explicitly stated in legislation and cannot be implied or inferred. Therefore, despite being chartered by Congress to facilitate interstate commerce through building bridges over navigable rivers, companies like Keokuk & Hamilton were still subject to regular tax laws unless specifically exempted by statute.

In the dissenting opinion for Keokuk & Hamilton Bridge Company v. United States, Justice McReynolds disagreed with the majority's interpretation of federal authority over bridges spanning navigable waters. He argued that while Congress has power to regulate commerce and navigation on such waterways, it does not have unlimited control over all structures crossing them. The bridge in question was built under state authority before any Congressional regulation existed; therefore, he believed it should be exempt from later federal requirements unless proven a significant obstruction to navigation. He also contended that the Court had no jurisdiction in this case as there was no controversy between two states or parties from different states - only an action by a U.S agency against a corporation operating entirely within one state’s boundaries. Furthermore, he asserted that if every structure across navigable rivers were subject to constant change due to evolving standards of convenience and safety, it would create uncertainty detrimental to public interests.