Andrés'brother, Pío Pico was the last Mexican Governor, who in 1848 signed the Treaty of Guadalupe Hidalgo formally ceding all of Mexico's Alta California territory to the United States.
Andrés'brother, Pío Pico was the last Mexican Governor. The last Mexican Governor in 1848 signed the Treaty of Guadalupe Hidalgo. This Guadalupe Hidalgo was formally ceding all of Mexico's Alta California territory to the United States.