P brought an action in Mississippi state court on a judgment entered in a Missouri state court. The dispute arose in Mississippi out of an illegal speculative transaction in cotton futures. The question was submitted to arbitration in Mississippi, but the illegality issue was not submitted. The decision was given to P, and while D was in Missouri, P served him, and P brought suit upon the arbitration award. During the Missouri trial, D was not allowed to show the illegality of the transaction. P got the judgment and brought the present action in Mississippi, and the trial court ordered judgment for P. The Mississippi Supreme Court reversed stating that the Missouri judgment was not entitled to the full faith and credit of Mississippi. The Supreme Court granted certiorari.