Encompassing more than 300 archival collections, the Huntington's California holdings are of the first rank for the study of the state's history. Materials range chronologically from the late 18th century to the present and consist of all manner of media, including manuscripts, books, broadsides, photographs, maps, audiovisual materials, and realia. English and Spanish are the two principal languages.
The Library's materials are strong in documenting the intertwined subjects of agriculture, ranchos and their families, and California's urban, water and power, and transportation infrastructures. Collections such as the 19th-century Abel Stearns papers and the 20th-century Southern California Edison records are among the Library's premier holdings on California land use and development. Also noteworthy is the Solano-Reeve collection, which contains over 2,100 maps and sketch maps of Los Angeles, Southern California ranchos, and subdivisions of the city of Los Angeles and neighboring towns. It provides invaluable material for studying the impact of development on successive populations.
California's legal and political history, including civil rights, is represented in the papers of lawyers such as Loren Miller and H. W. O'Melveny; governors and judges; and Los Angeles County and City officials. These holdings support collections on land use by documenting such issues as water rights. The Los Angeles County Court records, on long-term deposit, support scholarship related to the Los Angeles legal system and Southern California's social and ethnic history.
Personal diaries and letters, some dating to the 1870s, provide exceptional research opportunities for women's history. The papers of feminists such as Caroline Maria Seymour Severance and records of Southern California women's clubs like the Ebell Club are noteworthy 19th-century resources. In the 20th century, these strengths continue in holdings on professional women's organizations and businesswomen like Grace Nicholson.