[1] Founded in 1898, its mission is to aid Californians in tracing family history, through its research services, educational resources, online tools, and genealogical databases.

The CGS Research Library, one of the largest on the West Coast, contains over 38,000 reference materials from California and around the world.

[2] The California Genealogical Society was founded on February 12, 1898, in San Francisco.

[2] By 1913, the society had rebuilt its collection, growing to one of the largest in the West Coast.

[2] Since 2007, the society, its research library, and collections have all been housed in the historic Breuner Building in Oakland.