Charles W. Karthaus brought a case against Francisco Yllas y Ferrer and others in the Supreme Court of the United States. The dispute was over land that had been granted to Karthaus by Spain, but which he claimed had been wrongfully taken from him by Yllas and his associates. In order to resolve this issue, the court examined Spanish laws regarding property rights as well as documents related to the grant of land given to Karthaus. Ultimately, it found that while there were some irregularities in how ownership changed hands between parties involved, these did not invalidate Karthaus’s claim on the property; thus it ruled in favor of him and ordered for its return or compensation for its value at current market prices.

In the dissenting opinion of Charles W. Karthaus vs Francisco Yllas y Ferrer and Others, Justice Johnson argued that the plaintiff had no legal right to bring suit against the defendants in this case. He stated that since there was no contract between them, they were not bound by any law or obligation to each other. Furthermore, he noted that even if a contract did exist between them, it would be void due to its illegality under Spanish law at the time of its creation. In conclusion, Justice Johnson believed that since there was no valid agreement between parties and because all contracts made under Spanish law were invalidated upon American occupation of Florida in 1821; therefore Karthaus had no legal basis for his claim against Yllas y Ferrer and others.