Conner v. Long was a United States Supreme Court case that addressed the issue of whether a state court could issue a writ of habeas corpus to a prisoner held in a federal prison. The case arose when the petitioner, Conner, was convicted of a crime in the state of Georgia and sentenced to a term of imprisonment. Conner then filed a petition for a writ of habeas corpus in the state court, seeking to be released from the federal prison where he was being held. The state court granted the writ, and the federal government appealed the decision to the Supreme Court. 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 a federal prison. The Court reasoned that the writ of habeas corpus is a federal prerogative, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals. The Court also noted that the writ of habeas corpus is a fundamental right, and that the state court should not be allowed to interfere with the federal government's ability to exercise its power. 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 a federal prison. The Court reasoned that the writ of habeas corpus is a federal prerogative, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals. The Court also noted that the writ of habeas corpus is a fundamental right, and that the state court should not be allowed to interfere with the federal government's ability to exercise its power.

Justice Field delivered the dissenting opinion in Conner v. Long, arguing that the majority's decision was incorrect and should be reversed. He argued that under the terms of a contract between two parties, one party cannot unilaterally change or modify it without consent from both sides. In this case, he noted that Long had agreed to pay Conner $1 per acre for land but then attempted to reduce his payment after part of the land had already been conveyed by Conner to another party. Justice Field argued that such an action violated their agreement and constituted a breach of contract on behalf of Long; therefore, he concluded that Conner was entitled to recover damages for breach as well as specific performance if necessary.