Summary of Louisville & Nashville RR v. Mottley
211 U S 149 
Relevant Facts: The Mottleys were injured in a railway accident. To settle their claims, the RR gave them a lifetime pass good for free transportation on the line. Some time later Congress made that practice illegal to stymie bribes to public official with the passes. The RR thereafter refused to honor the Mottleys’ passes under the new legislation.
Legal Issue(s): Whether that part of the Act of Congress which makes it illegal to perform a contract for transportation, who before the passage of the Act, had accepted the same in satisfaction of a valid cause of action against the RR; and whether the Act is in violation of the 5th Amendment’s DP Clause?
Court’s Holding: Not necessary to consider; ct is w/o jurisdiction.
Procedure: APPEAL from U.S. Circuit Court granting Mottleys’ specific performance. Reversed and remanded with instructions to dismiss the suit for want of jurisdiction.
Law or Rule(s): A Pl shall be confined to a statement of its cause of action, leaving the Df to set up in his answer what his defense is and, if anything more than a denial of Pl’s cause of action.
Court Rationale: A suit arises under the Constitution and laws of the United States ONLY when
the Pl’s statement of his own cause of action shows that it is based upon those laws or the Constitution. The Pl’s original cause of action must arise under the Constitution or the laws/treaties of the U.S., not the DF’s defenses. A suggestion of one party, that the other will or may set up a claim under the Constitution or laws of the U.S., does not make the suit one arising under that Constitution or those laws. The ONLY way in which it might be claimed that a Fed Q was presented would be in the Pl’s complaint/statement of what the defense of Dfs would be and Pl’s answer to such a defense, not where the Pl’s cause of action is based upon the Dfs defense and answer that defense before the Df has answered or plead.
Plaintiff’s Argument: The Df and Pl had a contract for transportation which was made illegal by the Act of Congress, which is in violation of the 5th Amendment.
Defendant’s Argument: The Act of Congress made the contract illegal and Df can not be bound to an illegal contract by way of legislation of Federal law.