In June 1846, Frémont and Carson both participated in a California uprising against Mexico called the Bear Flag Revolt. Mexico ordered all Americans to leave California. They did not want to go, and declared California an independent republic. American settlers in California wanted to be free of the Mexican government. The Americans found courage to oppose Mexico because they had Frémont and his troops on board. Frémont wrote an oath of allegiance. He and his men were able to give some protection to the Americans. He ordered Carson to execute an old Mexican man named Berresaya and his two adult nephews. These three were captured when they stepped ashore at San Francisco Bay. They were executed to keep them from taking reports to Mexico about the uprising.