Ramsay v. Lee was a case heard by the United States Supreme Court in 1807. The dispute involved two men, Ramsay and Lee, who had entered into an agreement to purchase land from the Creek Indians in Georgia. However, when they failed to pay for the land as agreed upon, their contract was declared void by a lower court due to its violation of federal law prohibiting private citizens from purchasing Indian lands without government approval. On appeal before the Supreme Court, Ramsay argued that he should be allowed to keep his rights under the contract because it did not violate any laws at the time it was made and thus should remain valid despite subsequent legislation passed after its formation. Ultimately however, Chief Justice Marshall held that since Congress had prohibited such contracts after they were formed but before performance occurred on either side of them then those contracts could no longer be enforced even if they were legally binding prior to passage of this new law; therefore ruling against Ramsay and upholding cancellation of his contract with Lee regarding purchase of Creek Indian lands in Georgia.

In Ramsay v. Lee, the Supreme Court was tasked with determining whether a Maryland law that prohibited non-residents from bringing suits in state courts violated the Constitution's Contract Clause. The majority opinion held that it did not violate this clause because it applied equally to all citizens of other states and thus did not discriminate against any particular group or individual. However, Justice Samuel Chase dissented from this decision on two grounds: first, he argued that the law interfered with contracts made between individuals who were residents of different states; second, he contended that such a law could lead to an unequal application of justice depending on where one resided since some people would be able to bring suit while others would be unable to do so due to their residency status. Ultimately, Justice Chase concluded by asserting his belief that laws which interfere with contractual obligations should only be allowed if they are necessary for public safety or welfare and even then must still pass constitutional muster before being enacted into law.