The Sybil was a case heard by the US Supreme Court in 1819. The claimants, Dangerfield et al., were suing for damages due to an illegal seizure of their vessel and cargo. They argued that the seizure violated their rights under the Constitution as well as international law, which prohibited such seizures without just cause or legal authority. The court found in favor of Dangerfield et al., ruling that they had been wrongfully deprived of their property and should be compensated accordingly. This decision established important precedent regarding maritime law and affirmed individual's right to seek compensation when government action violates constitutional protections or international treaties.

In The Sybil, the Supreme Court was asked to decide whether a ship and its cargo were liable for duties imposed by Congress. A majority of justices held that they were not, but Justice Story dissented from this opinion. He argued that the Constitution gave Congress broad authority to impose taxes on imports and exports, including ships and their cargoes. Furthermore, he reasoned that since the duty had been paid before any legal proceedings began in this case, it should be considered valid even if it was later determined to have been improperly assessed or collected. Finally, he noted that there had already been numerous cases where similar duties had been upheld as constitutional despite challenges from claimants like those in this case. Therefore, Justice Story concluded that the duty should stand in The Sybil as well.