In 1871, the Mottleys (plaintiffs) were injured in a railway accident. The railroad, Louisville & Nashville Railroad (defendant), settled the Mottleys’ claims with a lifetime pass for free transportation on its line. In 1906, Congress passed an act forbidding passes granting free transportation. In 1907, the railroad refused to renew the Mottleys' passes. The Mottleys brought suit in federal district court, seeking specific performance of their settlement agreement with the railroad. The Mottleys alleged that the act did not apply to their free pass and that, if the law is construed as prohibiting such passes, it deprives them of their property in violation of the Fifth Amendment. The railroad demurred to the Mottley’s complaint. The trial court overruled the demurrer and entered judgment in favor of the Mottleys. The railroad appealed to the United States Supreme Court.