Erie doctrine

The great object of the Erie case was to secure in the federal courts, in diversity cases, the application of the same substantive law as would control if the suit were brought in the courts of the state where the federal court sits. It was the so-called 'federal common law' utilized as a substitute for state power, to create and enforce legal relationships in the area set apart in our scheme for state rather than for federal control, that the Erie decision threw out. Its object and effect were thus to bring federal judicial power under subjection to state authority in matters essentially of local interest and state control.