Willson v. The Black Bird Creek Marsh Company

A Delaware law authorized the Black Bird Creek Marsh Company (plaintiff) to build a dam across a small navigable creek feeding the Delaware River. The dam likely raised nearby property values and improved residents' health but obstructed a previously navigable creek. The owners of a boat (defendants) broke the dam and were sued for trespass. They challenged Delaware's authority to authorize the dam under the Commerce Clause.

Whether, under the Commerce Clause, a state may enact laws that affect commerce so long as they are not repugnant to Congress's power to regulate interstate commerce.