Understanding federal appellate jurisdiction is critical to any federal appeal because the federal right to appeal is primarily statutory and many federal statutes preclude appeals altogether. As a result, it is important for appellate practitioners to familiarize themselves with these statutes.
In 1810, the United States Supreme Court recognized that the U.S. Constitution gave the Court full jurisdiction, even if Congress had not specifically defined appellate jurisdiction in the Judiciary Act of 1789:
The appellate powers of this court are not given by the judicial act. They are given by the constitution. But they are limited and regulated by the judicial and by such other acts as have been passed on the subject.
Durousseau v. U.S., 10 U.S. 307, 313–14 (1810).