The Historical Society of Long Beach (HSLB) was formed in 1962 with the mission to collect, preserve, and present the city’s history. Throughout the years the HSLB has occupied many locations around the city, settling at its current location in Bixby Knolls in 2007. Operations are sustained at the HSLB by grant funding, membership dues, and community fundraising through programs and events.

The June L. Mazer Lesbian Collection, formerly the West Coast Lesbian Collections, was founded in Oakland, California, in 1981. Six years later it was moved to Los Angeles by Connexxus Women's Center/Centro de Mujeres, and it acquired its present name in 1987 after the death of June L. Mazer, a community activist and an invaluable supporter of the collection.

The Southern California Library for Social Studies and Research primarily documents and preserves the history of twentieth-century radicalism and social change through progressive movements in the greater Los Angeles area. The materials held by the library relate to the labor, peace, social justice, civil rights, women’s, gay and lesbian, and various other grassroots movements.