Green v. Van Buskirk was 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 held in federal custody. The case arose when a prisoner, John Green, was arrested by federal authorities in California and held in federal custody. Green then filed a petition for a writ of habeas corpus in the California state court, seeking to be released from federal custody. The federal government argued that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The Supreme Court ultimately held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The Court reasoned that the writ of habeas corpus was a federal prerogative, 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 fundamental right, and that the federal government had the exclusive power to protect that right. In conclusion, the Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The Court reasoned that the writ of habeas corpus was a federal prerogative, and that the state court did not have the authority to interfere with the federal government's power to detain a prisoner.

In Green v. Van Buskirk, the Supreme Court was asked to decide whether a state statute that allowed for the sale of real estate belonging to minors without court approval violated the Fourteenth Amendment's Equal Protection Clause. The majority opinion held that it did not violate equal protection because there were reasonable distinctions between adults and minors in terms of their ability to manage property. However, Justice Field dissented from this decision, arguing that allowing such sales without court approval created an unequal burden on minors by depriving them of their right to due process and equal protection under law. He argued that all persons should be treated equally before the law regardless of age or other characteristics and thus concluded that such a statute was unconstitutional as it denied these rights to minors who could not protect themselves against unfair treatment in legal proceedings concerning their property rights.