Cases that arise under a federal law (called "federal question" cases). Federal district courts have subject matter jurisdiction if your case is based on (arises under) any federal law. Examples include:
•You sue a police officer for violating a federal civil rights statute that authorizes civil damages lawsuits by persons who are unlawfully arrested.
diversity of citizenship cases. Federal district courts also have subject matter jurisdiction if you are suing a citizen of a different state (or a foreign national), and you are asking for at least $75,000 in money damages. (The minimum dollar amount may be responsible for the old saying, "Don't make a federal case out of it.") If a federal court has jurisdiction based on diversity of citizenship, the subject matter of the case doesn't matter. Examples of federal diversity jurisdiction include:
•A citizen of New York injured in a traffic accident sues the New Jersey citizen who was driving the car, and the complaint asks for damages in excess of $75,000. (The injured party could file the complaint in a federal court in either New York or New Jersey.)
"Complete diversity" must exist. Federal courts have diversity jurisdiction only if there is "complete diversity" between plaintiffs and defendants. For diversity jurisdiction purposes, individuals are generally citizens of the state in which they maintain a principal residence, and they can be a citizen of only one state at a time.