28 U.S.C. § 1391 is a federal statute that governs the proper venue for civil actions in the United States. This statute establishes the specific circumstances under which a lawsuit can be brought in a federal district court, ensuring that cases are filed in locations that are convenient and relevant to the parties involved and the events in question. The rules outlined in this section are essential for determining where a case should be heard, thus impacting the efficiency and fairness of the judicial process.