The federal judges in the appeals courts have an even more difficult task keeping up with all the work. The U.S. court system has three levels. In the lowest level are the district courts. Next are the U.S. Courts of Appeals, or U.S. Circuit Courts. Finally at the top is the U.S. Supreme Court.
Most cases begin and end in the district courts.
These are located throughout the country in different zones or districts. For example, John Doe was accused of breaking into a post office in a town outside Pittsburgh. His trial therefore took place in the federal district court in Pittsburgh. There is another district court in the middle of Pennsylvania and a third district court for eastern Pennsylvania. A fourth district court serves all of Delaware and a fifth serves all of New Jersey.