Give a stream of consciousness and then the final answer. The Supreme Court of the United States, established in 1789, is the highest federal court in the United States, with powers of judicial review first asserted in Calder v. Bull (1798) in Justice Iredell's dissenting opinion. The power was later given binding authority by Justice Marshall in Marbury v. Madison (1803). There are currently nine seats on the US Supreme Court.

Answer this question: who or what serves as the last or highest source for legal disputes in the united states?
The relevant information is: The Supreme Court of the United States, established in 1789, is the highest federal court in the United States, with powers of judicial review first asserted in Calder v. Bull (1798) in Justice Iredell's dissenting opinion.
So, the final answer is The Supreme Court of the United States.