In Ewell v. Daggs, 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 was being held in federal custody. The petitioner, Ewell, was a prisoner in the custody of the United States Marshal for the District of Columbia. He had been convicted of a crime in the District of Columbia and was serving a sentence in the federal penitentiary. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner in federal custody. The Court reasoned that the power to issue a writ of habeas corpus was a power reserved to the federal government, and that the state court did not have the authority to interfere with the federal government's power to detain a prisoner. The Court also noted that the writ of habeas corpus was a remedy available to prisoners in federal custody, and that the state court did not have the authority to interfere with the federal government's power to detain a prisoner. The Court's decision in Ewell v. Daggs established that the state court did not have the authority to issue a writ of habeas corpus to a prisoner in federal custody. The decision reaffirmed the principle that the federal government has exclusive authority over matters involving federal prisoners.

Justice Field delivered the dissenting opinion in Ewell v. Daggs, arguing that the majority had erred in their interpretation of a contract between two parties. He argued that the Court should have looked at all of the evidence presented to them and not just relied on one document as they did when deciding this case. The contract was ambiguous and could be interpreted differently depending on which documents were considered; however, Justice Field believed that all relevant documents should have been taken into account before making a decision. He also noted that there was no clear indication from either party as to what their intentions were with regard to this particular agreement, so it would be unfair for the court to make such an important ruling without considering every aspect of it first. In conclusion, he felt strongly that if more attention had been paid to all aspects of this case then perhaps a different outcome may have resulted instead.