In O'Brien v. Weld et al., the United States Supreme Court was asked to decide whether a state court had the authority to issue a writ of habeas corpus to a prisoner who had been convicted in a federal court. The petitioner, O'Brien, had been convicted in a federal court of violating the federal Neutrality Act. He then sought a writ of habeas corpus from a state court, claiming that his conviction was unconstitutional. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus in this case. The Court reasoned that the writ of habeas corpus was a federal remedy, and that the state court did not have the power to interfere with the federal court's decision. The Court also noted that the writ of habeas corpus was not available to challenge the constitutionality of a federal conviction. The Court's decision in O'Brien v. Weld et al. established that state courts do not have the authority to issue writs of habeas corpus to challenge the constitutionality of federal convictions. This decision has been cited in numerous subsequent cases, and it remains an important precedent in the area of federal-state relations.

Justice Field delivered the dissenting opinion in O'BRIEN v. WELD et al., arguing that the majority's decision was contrary to both precedent and sound legal reasoning. He argued that it should not be assumed, as the majority had done, that a state legislature has authority to pass laws which are unconstitutional or repugnant to other laws of Congress; rather, he maintained that such legislation must be tested by its conformity with federal law before being declared valid or invalid. Furthermore, Justice Field contended that even if Massachusetts had passed a law allowing for imprisonment of debtors without due process of law - something which he did not believe they had actually done - such an act would still have been unconstitutional under Article I Section 10 Clause 1 of the United States Constitution (the Contract Clause). In conclusion, Justice Field believed there were sufficient grounds for reversing the judgment below and remanding this case back to Massachusetts courts for further proceedings consistent with his interpretation of applicable constitutional principles.