This authoritative text lays out the constitutional and statutory sources of federal judicial authority, its limits, and how the Supreme Court directs its exercise. Some limits are constitutional, others statutory, and many others self-imposed. There is extended consideration of constitutional and statutory federal-question jurisdiction (including a step-by-step method for discovering whether an allegation is well-pleaded), diversity jurisdiction, abstention, sovereign immunity and the Eleventh Amendment, official immunities, congressional control of federal jurisdiction, and the law applicable in the federal courts-the dreaded (but eminently sensible and really not so scary) Erie doctrine.