Thompson v. Bowie was a United States Supreme Court case that was decided in 1866. The case involved a dispute between two parties over the ownership of a slave named Bowie. The plaintiff, Thompson, claimed that he had purchased Bowie from a third party and was the rightful owner. The defendant, Bowie, argued that he was a free man and had never been a slave. The Supreme Court ultimately sided with Thompson, ruling that the plaintiff had established a valid title to Bowie and that the defendant had no legal right to the slave. The Court held that the plaintiff had acquired a valid title to Bowie through the purchase from the third party, and that the defendant had no legal right to the slave. The Court also held that the defendant had no right to challenge the validity of the title, as he had not been a party to the transaction. The decision in Thompson v. Bowie established that a valid title to a slave could be acquired through a purchase from a third party, and that the validity of the title could not be challenged by someone who was not a party to the transaction. This decision was an important step in the development of the law of slavery in the United States.

In Thompson v. Bowie, the Supreme Court was asked to decide whether a deed of trust executed by an individual in favor of another could be enforced against third parties who had purchased property from the debtor without knowledge or notice of the deed. The majority opinion held that such a deed was enforceable and that purchasers were bound by it even if they did not have actual knowledge or notice at the time of purchase. Justice Field dissented on this point, arguing that purchasers should not be held liable for debts incurred prior to their acquisition of title unless they had actual knowledge or notice at the time when they acquired title. He argued further that any other rule would lead to great injustice as innocent purchasers would suffer losses due to no fault on their part and creditors would receive more than what is justly due them under existing laws.