The Sally Magee was a case heard by the United States Supreme Court in 1865. The case involved a dispute between two parties over ownership of a schooner, the Sally Magee. One party claimed that they had purchased the vessel from its original owner and thus held title to it; however, another party argued that they were entitled to possession of the ship as payment for services rendered while it was being built. After hearing arguments from both sides, the court determined that since there was no evidence presented showing any transfer of title or delivery of possession at any point prior to when one party took control of it, then this first party must be considered rightful owners and possessors. As such, their claim should be upheld and recognized as valid under maritime law.

In the case of The Sally Magee, the Supreme Court was asked to decide whether a ship that had been seized by Confederate forces during the Civil War could be considered a prize of war and thus subject to condemnation. The majority opinion held that since it was not possible for either side in the conflict to have lawfully acquired title or possession of such property at any time prior to its seizure, then no valid claim existed as against either party. Justice Field dissented from this decision on two grounds: first, he argued that under international law it is well established that vessels captured by one belligerent are lawful prizes; second, he contended that even if there were some doubt about this principle under domestic law, Congress had expressly provided for such seizures through legislation passed shortly before hostilities began. He concluded his dissent with an observation regarding how difficult it would be for those who owned ships taken during wartime without being able to recover them due to lack of legal standing.