Why Two Court Systems?
The Judicial Branch has two court systems: federal and state. While each hears certain types of cases, neither is completely independent of the other. The two systems often interact and share the goal of fairly handling legal issues.
The U.S. Constitution created a governmental structure known as federalism that calls for the sharing of powers between the national and state governments. The Constitution gives certain powers to the federal government and reserves the rest for the states.
The federal court system deals with legal issues expressly or implicitly granted to it by the U.S. Constitution. The state court systems deal with their respective state constitutions and the legal issues that the U.S. Constitution did not give to the federal government or explicitly deny to the states.
For example, because the Constitution gives Congress sole authority to make uniform laws concerning bankruptcies, a state court would lack jurisdiction. Likewise, since the Constitution does not give the federal government authority in most family law matters, a federal court would lack jurisdiction in a divorce case.