Although the Treaty of Guadalupe Hidalgo formally protected the legal rights of Mexicans now part of the United States, a long legal challenge to Vallejo's land title cost him thousands of dollars in legal fees and finally deprived him of almost all his land and farm animals. Most Californios could not afford the legal expenses to claim their lands, which were thus lost to wealthy Americans and the flood of immigrants, beginning with the Gold Rush, which left the Californios outnumbered and unable to protect their political power. At some time prior to 1869, Vallejo gave the Mexican land grant Rancho Suscol to his daughter, Epifania Guadalupe Vallejo, April 3, 1851, as a wedding present, when she married General John B. Frisbie.