Immigration is exclusively federal law. The Federal court system is divided into three levels: district courts, circuit courts of appeal, and the U.S. Supreme Court.
The decision of a court has precedential value only within the court's territorial jurisdiction. For example, the opinions of the Supreme Court have precedential value nationally because all lower courts must follow its decisions. The decisions of a court of appeals bind the courts within the circuit’s jurisdiction. However, decisions of a federal district court are not binding on federal courts in any other district.
District courts are the trial bodies of the federal court system. Some states have only one district court while other states have several district courts. Decisions by judges within the same district can influence rulings in similar cases. However, a district court judge will occasionally certify a case as a class action suit and then enter an injunction that applies to all members of the defined class. If the members of the class are located nation-wide, the injunction applies nationally.
Appeals from a district court are taken to the courts of appeal in 13 circuits. Again, decisions by one of these courts are binding only upon the district and circuit court judges within that circuit. While an interpretation of law is binding only on judges in that circuit, judges can look to other circuits for decisions which are similar to cases being decided within their circuit.
The Supreme Court of the United States generally hears appeals from the circuit courts of appeal. Decisions of the Supreme Court are binding upon all U.S. courts.
Westlaw has an immigration cases database that can be found by clicking on Practice Areas, then Immigration. It includes cases from the U.S. Supreme Court, courts of appeals, district courts, bankruptcy courts, Court of Federal Claims, Tax Court, military courts, and related federal and territorial courts that relate to the rights and disabilities of foreign persons in the United States. Coverage begins with 1789.
Lexis Advance has a similar database, which can be found by clicking on Practice Area, and then Immigration.
Lexis is available on the Franklin County Law Library public access computers.