In the 1890 case of Manning v. Amy, the US Supreme Court ruled on a dispute involving maritime law and salvage rights. The plaintiff, Manning, had salvaged a sunken ship owned by Amy in Lake Erie and sought compensation for his efforts. However, he did not have an agreement with Amy prior to undertaking the salvage operation. The court held that while it is generally accepted under maritime law that those who voluntarily save another's property from peril at sea are entitled to compensation even without pre-existing contractual obligation (a principle known as "salvage"), this rule does not apply within bodies of water entirely enclosed within one state - such as Lake Erie - because they fall outside federal jurisdiction over admiralty matters. Therefore, since there was no contract between Manning and Amy regarding any potential salvage operations or rewards thereof before he proceeded with his actions, Manning could not claim any right to payment under federal maritime laws.

In the dissenting opinion for Manning v. Amy, it was argued that the majority's decision to uphold a Louisiana law requiring all commercial transactions involving cotton to be conducted in public places was an overreach of state power and violated the Commerce Clause of the U.S. Constitution. The dissenting justices believed that this law interfered with private business transactions between individuals from different states, which should fall under federal jurisdiction as interstate commerce rather than being regulated by individual state laws. They contended that while states have broad powers to regulate local matters, they cannot use these powers in ways that interfere with or burden interstate commerce - something they felt this law did by dictating where and how such transactions could take place.