California Department

The California Department was a department of the Second Mexican Empire, located in Northwestern Mexico.
The department included all the Baja California peninsula. It did not include any of the former Alta California, which was ceded to the U.S. in 1848 under the Treaty of Guadalupe Hidalgo.
It was established by an imperial decree on March 3, 1865, which specified:
The present-day Mexican states of Baja California and Baja California Sur are located where the department was.