In Hudson v. Parker, the U.S. Supreme Court ruled on a dispute involving maritime law and salvage rights. The case arose when the steamship "Hudson" collided with another vessel in Lake Erie, causing significant damage to both ships. A third party, Mr. Parker, intervened to save the sinking vessels and their cargo from total loss by towing them into port for repairs. The owners of the "Hudson" argued that they owed no compensation to Mr. Parker because he had not been officially contracted as a salvor but was merely fulfilling his duty as a fellow seaman under maritime law - an obligation known as 'the duty of succour'. However, Mr.Parker claimed that his actions went beyond this basic responsibility and constituted an act of salvage which should be rewarded accordingly. The court sided with Mr.Parker stating that while all mariners have a legal obligation to assist others in distress at sea without expectation of reward (duty of succour), those who go above and beyond this requirement are entitled to claim remuneration for their efforts if they successfully preserve life or property at risk. Therefore it held that even though there was no formal agreement between parties involved regarding payment for services rendered during rescue operations; anyone who voluntarily saves another's property from impending peril is eligible for fair compensation based on principles governing marine salvage operations.

In the dissenting opinion for Hudson v. Parker, it was argued that the majority's decision to uphold a Michigan law prohibiting non-residents from fishing in its waters with nets violated the Commerce Clause of the U.S. Constitution. The dissenting justices believed that this law unfairly discriminated against out-of-state fishermen and impeded interstate commerce by restricting their access to a natural resource found within Michigan’s borders - fish in public waters - which they viewed as part of national commerce. They contended that states should not have unilateral control over resources like these, especially when such control could negatively impact trade between states or give one state an unfair advantage over others. Therefore, they disagreed with upholding a statute that allowed such discrimination and restriction on interstate commerce.