Hannah Riley v. William B. Welles was a case heard by the United States Supreme Court in 1869. The case involved a dispute between Riley and Welles over a contract for the sale of a parcel of land in the state of Ohio. Riley had agreed to purchase the land from Welles for a certain sum of money, but Welles refused to accept the payment and instead sought to keep the land for himself. The Supreme Court ruled in favor of Riley, finding that the contract between the two parties was valid and enforceable. The Court held that Welles had breached the contract by refusing to accept the payment and that Riley was entitled to the land as agreed upon in the contract. The Court also held that Welles was liable for damages for his breach of contract. The decision in this case established the principle that contracts are binding and enforceable in the United States. It also established the principle that a party who breaches a contract is liable for damages. This case is still cited today as an important precedent in contract law.

In the case of Hannah Riley v. William B. Welles, the Supreme Court was asked to decide whether a married woman had the right to sue in her own name for damages caused by another person's negligence. The majority opinion held that she did not have such a right and that any claim must be brought through her husband as guardian or trustee on behalf of his wife and children. Justice Field wrote a dissenting opinion arguing that this decision would deny married women their rights under state law which allowed them to bring suits in their own names without having to go through their husbands first. He argued further that denying these rights violated both natural justice and public policy since it prevented women from protecting themselves against wrongs done against them while allowing men full access to legal remedies available under state law regardless of marital status.