The United States v. William Murphy and William Morgan was a Supreme Court case that centered around the issue of whether or not Congress had the authority to pass laws regulating foreign commerce. The defendants, Murphy and Morgan, were accused of violating an act passed by Congress in 1817 which prohibited American citizens from trading with certain countries without permission from the President. They argued that this law exceeded Congressional power under Article I Section 8 of the Constitution which grants Congress only limited powers over foreign trade. The Supreme Court ultimately ruled against them, finding that while there are limits on what can be regulated through legislation related to foreign commerce, it is within Congress’s power to regulate such matters as long as they do so for “the general welfare” of all Americans. This ruling established a precedent for future cases involving federal regulation of international trade and affirmed congressional authority over such matters even when individual rights may be affected in some way

In the case of The United States v. William Murphy and William Morgan, Justice McLean delivered a dissenting opinion in which he argued that Congress had no authority to pass the law under which the defendants were charged with violating. He reasoned that this was because it was not within any of its enumerated powers as outlined by Article I, Section 8 of the Constitution. Furthermore, he noted that if such power did exist then it would be an unconstitutional delegation of legislative authority to executive officers since they were responsible for enforcing it without congressional oversight or control. Finally, Justice McLean concluded his dissent by stating that even if Congress could pass such laws they should only do so when necessary and proper for carrying out their other constitutional duties; however here there was no evidence presented showing how this particular law served any purpose related to those duties.