Stryker v. Goodnow's Administrator was a United States Supreme Court case that dealt with the issue of whether a state court had the authority to grant a new trial in a case that had already been decided by a federal court. The case arose when the plaintiff, Stryker, sued the defendant, Goodnow's Administrator, in a state court for breach of contract. The state court found in favor of Stryker and awarded him damages. Goodnow's Administrator then appealed the decision to a federal court, which reversed the state court's decision and dismissed the case. Stryker then sought a new trial in the state court, which the state court granted. Goodnow's Administrator then appealed the state court's decision to the Supreme Court. The Supreme Court held that the state court did not have the authority to grant a new trial in a case that had already been decided by a federal court. The Court reasoned that the state court's decision was in conflict with the federal court's decision and that the state court was not authorized to review the federal court's decision. The Court also noted that the state court's decision was in violation of the Supremacy Clause of the United States Constitution, which states that federal law is the supreme law of the land. In conclusion, the Supreme Court held that the state court did not have the authority to grant a new trial in a case that had already been decided by a federal court. The Court reasoned that the state court's decision was in conflict with the federal court's decision and that the state court was not authorized to review the federal court's decision.

In Stryker v. Goodnow's Administrator, the Supreme Court was asked to decide whether a state court had jurisdiction over an action brought by a citizen of one state against another in which the defendant resided in yet another state. The majority opinion held that such an action could not be maintained without violating the Full Faith and Credit Clause of the Constitution, as it would require two states to give effect to judgments rendered by courts of other states. Justice Field dissented from this decision, arguing that there is no constitutional prohibition on suits between citizens of different states when they are brought before their own respective tribunals; rather, he argued that such actions should be allowed so long as each party has access to justice within its own borders and can obtain full relief for any wrongs suffered. He further noted that allowing these types of suits would promote comity among all parties involved and ensure fairness across jurisdictional lines.