Ashmore heirs to arrest and return Morgan to their estate in Maryland. In a ruling on May 22, 1839, the Court of Quarter Sessions of York County convicted him of violation of the state law. Prigg appealed to the US Supreme Court on the grounds that the Pennsylvania law was not able to supersede federal law or the US Constitution; the Fugitive Slave Act and Article IV of the Constitution were in conflict with the Pennsylvania law of 1788. The case was Prigg v. Pennsylvania, 41 U. S. 539 (1842). Prigg and his lawyer argued that the 1788 and 1826 Pennsylvania laws were unconstitutional: First, because of the injunction in Article IV of the US Constitution: "No person held to service or labor in one state, under the laws thereof, escaping into another, shall, in consequence of any law or regulation therein, be discharged from such service or labor; but shall be delivered up, on claim of the party to whom such service or labor may be due." Second, because the exercise of Federal legislation, such as that undertaken by Congress in passing the act of the February 12, 1793, supersedes any state law. As a consequence, they argued, the 1788 Pennsylvania law, in all its provisions applicable to this case, should be voided. The question was whether Pennsylvania law violated the constitutional guarantee of fugitive slave return and the 1793 Act of Congress, passed to implement it. Decision Writing for the Court, Justice Joseph Story reversed the conviction and held the Pennsylvania law was unconstitutional, as it denied both the right of slaveholders to recover their slaves under Article IV and the Federal Fugitive Slave Law of 1793, which trumped the state law per the Supremacy Clause. Six justices wrote separate opinions. Although Story ruled the Pennsylvania laws were unconstitutional, his opinion left the door open for the state to forbid state officials to cooperate in the return of fugitive slaves: As to the authority so conferred upon state magistrates [to deal with runaway slaves], while a difference of opinion has existed, and may exist still on the point, in different states, whether state magistrates are bound to act under it; none is entertained by this Court that state magistrates may, if they choose, exercise that authority, unless prohibited by state legislation. However, state laws could not interfere with a slave-owner's right to go to another state and recapture