In the United States, removal jurisdiction allows a defendant to move a civil action filed in a state court to the United States district court in the federal judicial district in which the state court is located. A federal statute governs removal. Generally, removal jurisdiction exists only if, at the time plaintiff filed the action in state court, the federal court had a basis for exercising subject-matter jurisdiction over the action, such as diversity of citizenship of the parties or where plaintiff's action involves a claim under federal law. If removal is based solely on diversity of citizenship, removal jurisdiction does not exist if any properly joined and served defendant is a citizen of the state in which the action is pending. Where removal jurisdiction exists, the defendant may remove the action to federal court by filing a notice of removal in the federal district court within 30 days after receiving the complaint. The defendant must file a copy of the notice of removal in the state court and must notify all other parties of the removal. In a case with more than one named defendant, normally all defendants who have been served with legal process must join in the notice of removal. If the party contends that removal was improper, based on any ground other than that the federal district court lacks subject matter jurisdiction, the party may move the district court to remand the case to state court within 30 days after the defendant filed the notice of removal. The district court will grant the motion if it finds that removal was improper. If the district court determines that it lacks subject matter jurisdiction at any time before entry of final judgment, the district court must remand the action to the state court. The Class Action Fairness Act of 2005 creates a separate basis for defendants to remove specified class actions filed in a state court to a federal district court. History The Judiciary Act of 1789 initially provided for removal jurisdiction. The Jurisdiction and Removal Act of 1875 explicitly granted federal courts jurisdiction over questions arising under federal law. The Judiciary Act of 1887 limited removal to defendants and established the well pleaded complaint requirement for removal. Removal and complete diversity When there are multiple defendants in a case, if even just one is a citizen of the state where the lawsuit was filed, a plaintiff can