The Mary and Susan was a case heard before the United States Supreme Court in 1816. The claimants, G. & H. Van Wagenen, were seeking compensation for damages to their vessel caused by an American privateer during the War of 1812. The court found that while there had been no actual seizure or detention of the ship, it had still suffered damage due to its proximity to hostile forces and thus should be compensated accordingly under international law principles as established by Congress in 1793. Ultimately, the court ruled that G&H Van Wagenen were entitled to receive payment from either France or Great Britain for their losses since both countries had contributed naval vessels towards causing such harm upon neutral ships like theirs during wartime operations on open seas.

In The Mary and Susan case, the Supreme Court was asked to decide whether a vessel that had been captured by an enemy during wartime could be considered abandoned. The majority opinion held that the vessel should not be considered abandoned because it had been taken from its owners without their consent or knowledge. However, in his dissenting opinion Justice Story argued that since the vessel was no longer under the control of its owners and they were unable to recover it due to circumstances beyond their control, then it should be deemed as having been effectively abandoned. He further noted that if such vessels were allowed to remain in enemy hands indefinitely, this would lead to great hardship for those who owned them as well as put other vessels at risk of capture due to lack of protection from friendly forces. Therefore he concluded that even though there may have been some degree of uncertainty surrounding ownership rights over these vessels after capture by an enemy force, they still ought to be treated as being effectively abandoned so long as reasonable efforts have failed or are likely fail in recovering them.