Online Archive of California (OAC)

Overview

The Online Archive of California (OAC) is a service of the University of California Libraries, developed and maintained by the California Digital Library (CDL). It provides free public access to descriptions, or "finding aids," of primary source collections held by libraries, museums, archives, and other institutions across California.

History

OAC originated as the UC-EAD project, built on the Encoded Archival Description (EAD) standard developed at UC Berkeley. In June 1997 participation was extended to non-UC California repositories, and the project was renamed the Online Archive of California. In 1998 it was formally integrated into the California Digital Library. CDL subsequently launched the Japanese American Relocation Digital Archive (JARDA) and Museums and the Online Archive of California (MOAC) projects, the Local History Digital Resources Project (2001), and California Cultures (2006). In July 2025, CDL launched an upgraded version of OAC rebuilt with open-source technologies.

Collections, Holdings, and Publications

OAC provides access to more than 78,000 finding aids from more than 350 contributing institutions statewide, including the ten University of California campuses, public and academic libraries, museums, and historical societies. Primary sources described include letters, diaries, manuscripts, legal and financial records, photographs, maps, architectural and engineering records, artwork, scientific logbooks, sound recordings, oral histories, and ephemera.

Access and Usage

OAC is freely accessible online and open to new contributing institutions, including California academic, public, or private libraries, special collections, archival repositories, historical societies, and museums.