In Blakeney v. Evans, the Supreme Court of the United States held that a state court could not issue an injunction to prevent a federal court from exercising its jurisdiction over a case. The dispute arose when William Blakeney sued John Evans in Georgia's Superior Court for trespass and damages related to land disputes between them. After filing his suit, Blakeney sought an injunction from the same court against any proceedings in federal courts concerning the same matter. The Supreme Court ruled that such an action was beyond the power of state courts because it interfered with federal judicial authority and violated Article III of the Constitution which grants exclusive jurisdiction over cases arising under laws made by Congress or treaties made by foreign nations to U.S district courts and ultimately to this nation’s highest tribunal -the US Supreme Court itself- as established by law . Therefore, they concluded that states cannot interfere with matters within their own jurisdictions but must respect those belonging exclusively to other sovereign powers like those granted through constitutional provisions regarding judicial authority vested solely in Federal Courts

In Blakeney v. Evans, the Supreme Court was asked to decide whether a state court had jurisdiction over a case involving an alleged breach of contract between two citizens from different states. The majority opinion held that the state court did not have jurisdiction in this matter because it involved interstate commerce and thus fell under federal authority. However, Justice Chase dissented on the grounds that Congress had never explicitly granted exclusive power to regulate interstate commerce to itself or any other branch of government; therefore, he argued that individual states should be allowed to exercise their own powers in such matters as long as they do not conflict with existing laws passed by Congress. He also noted that allowing each state its own authority would help ensure uniformity among all jurisdictions and prevent one party from gaining an unfair advantage over another due solely to differences in local law or regulation.