245 (1829),[1] was a significant United States Supreme Court case regarding the definition of the Commerce Clause in Article 1 sec.

Willson, the owner of a sloop who was licensed under federal navigation laws, the Sally, broke through a dam that blocked his passage which was built by the Black-Bird Creek Marsh Co. and had been authorized to do so by Delaware law.

The company brought a case against Willson, claiming Delaware authorized the building of the dam on the Blackbird Creek through a law which was passed under the police power of the state in order to clean up a health hazard and there was no legislation by Congress dealing with the same subject matter.

Willson claimed that the law authorizing the building of the dam was a violation of the commerce clause.

He believed he had a constitutional right to navigating coastal streams and Delaware's actions were motivated by private profits.