Adams, Qui Tam v. Woods is a landmark Supreme Court case that established the concept of qui tam lawsuits in the United States. The plaintiff, Adams, was an informer who had brought suit against Woods for violating a federal statute prohibiting private individuals from trading with Native Americans without permission from Congress or other authorized officials. In his ruling on this case Chief Justice John Marshall held that when someone brings suit under such statutes they are entitled to receive half of any fines imposed as compensation for their efforts in bringing about justice and enforcing laws passed by Congress. This decision set an important precedent which has been used ever since to allow citizens to bring suits against those who violate federal law and be rewarded financially if successful.

In Adams, Qui Tam v. Woods, the Supreme Court was asked to decide whether a qui tam action could be brought by an individual for violations of public law that had occurred prior to the passage of the Judiciary Act of 1789. The majority opinion held that such actions were not allowed under existing laws and thus dismissed the case. In his dissenting opinion, Justice Samuel Chase argued that Congress had intended for individuals to have standing in these types of cases as evidenced by their inclusion in English common law and other statutes passed after 1789 which explicitly granted this right. He further noted that allowing private citizens to bring suit would help ensure compliance with public laws since it would provide a powerful incentive for those who violated them - namely potential financial penalties imposed by courts or juries if found guilty - while also providing much needed resources when governments lacked sufficient funds or personnel necessary to enforce them on their own.