The California colonists from the United States gradually became more and more bitter against the Mexican local government.
Mexican government
In 1821, Mexico gained independence from Spain, and in 1825, after several years of self-government, the region, later named Alta California, was formally declared a territory of the Mexican Republic.
European research
The first European to visit these lands was Juan Rodriguez Cabrillo. In 1542, Cabrillo landed with his soldiers on the shores of the bay he named San Diego and continued his explorations of the California