Ex parte Brown & Another is a United States Supreme Court case that dealt with the issue of 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 case involved two prisoners, William Brown and John Smith, who were being held in federal custody in the state of Virginia. The state court had issued a writ of habeas corpus to the federal authorities, ordering them to produce the prisoners in court. The federal authorities refused to comply with the writ, arguing that the state court did not have the authority to issue such a writ. The Supreme Court held that the state court did have the authority to issue the writ of habeas corpus. The Court reasoned that the writ of habeas corpus is a fundamental right that is guaranteed by the Constitution, and that the state court had the authority to issue the writ in order to protect the rights of the prisoners. The Court also noted that the federal government had not challenged the state court's authority to issue the writ, and thus the writ was valid. As a result, the Supreme Court ordered the federal authorities to comply with the writ and produce the prisoners in court.

In Ex Parte Brown & Another, the Supreme Court was asked to decide whether a state court had jurisdiction over an action brought by two citizens of one state against another citizen of that same state. The majority opinion held that the case should be heard in federal court because it involved citizens from different states and therefore fell under the diversity clause of Article III, Section 2 of the Constitution. However, Justice Field dissented from this decision on several grounds. He argued that Congress did not have authority to expand federal judicial power beyond what was granted by Article III; he also noted that there were no allegations or evidence presented which would suggest any kind of discrimination based on race or other protected classifications as required for cases involving diversity jurisdiction. Furthermore, he argued that if Congress could extend its powers through legislation such as this then it would lead to further erosion of states' rights and ultimately undermine our system's separation-of-powers structure. In conclusion, Justice Field believed strongly in upholding both constitutional principles and protecting states’ rights when deciding matters related to federalism so he disagreed with his colleagues’ ruling in this case.