Abstract: Federal courts are courts of limited jurisdiction—but only in part. A federal court’s subject-matter jurisdiction is limited by the Constitution; its territorial, personal jurisdiction is not. Current doctrine notwithstanding, a federal court’s writ may run as far as Congress, within its enumerated powers, would have it go. Today’s doctrine limits federal jurisdiction by borrowing Fourteenth Amendment principles thought to govern state courts. This borrowing blocks recoveries by injured plaintiffs, such as American victims of foreign terrorist attacks; and it’s become a font of confusion for procedure scholars, giving rise to incisive critiques of the Federal Rules. It’s also a mistake. The Fourteenth Amendment didn’t impose new limits on state personal jurisdiction; it enabled federal enforcement of limits that already applied. Current doctrine retroactively forces the Fifth Amendment into the mold of the modern Fourteenth, transforming an expansion of federal power into a strict constraint on federal authority. The federal courts’ territorial jurisdiction depends, in the first instance, on Congress’s powers. It may be that Congress can authorize fully global jurisdiction over any suit within Article III. If not, Congress may have ways to make better use of its jurisdictional powers at home. Either way, the existing mix of statutes and procedural rules seems fully valid. If the Constitution didn’t impose limits on Congress or on the federal courts, modern doctrine shouldn’t either.