  However, a dizzying series of Supreme Court opinions—the Antelope (1825), the Amistad (1841), Groves v. Slaughter (1841), Prigg v. Pennsylvania (1842), and Strader v. Graham (1850)—culminating in the Dred Scott opinion (1856) helped undermine that theoretical approach. These cases each helped clarify the legal scope of black civil rights, in a way generally unfavorable to blacks. The rebellion on the Amistad would have led to restoring kidnapped black Africans to their purported Spanish owners if narrow questions of international treaty obligations had been read differently. The slave status of blacks was not affected by their transient residence in a free state, as was held in Strader. Fugitive slaves were presumed to be subject to return, as the Court held in Prigg, despite the somewhat weaker obligation of states to carry out the requisite extraditions. The difficulty presented by this series of opinions is well captured by the Court's interpretation of fugitive slave laws, and shows the headwind against Crummell.