History of the Counties in California
Butte, Calaveras, Colusa, Contra Costa, El Dorado, Los Angeles, Marin, Mariposa, Mendocino, Monerey, Napa, San Diego, San Francisco, Santa Clara, Santa Cruz, Shasta, Solano, Sonoma, Sutter, Sacramento, Santa Barbara, San Joaquin, Trinity, Tuolumne, Yolo, Yuba,
Added in 1851- Placer, Nevada
Added in 1952 - Sierra, Siskiyou, Tulare
Added in 1853 - Alameda, Humboldt, San Bernardino
Added in 1854 - Stanislaus, Amador, Plumas
Added 1855 - Merced.
Added in 1856 - Fresno Tehama, San Mateo
Added in 1857 - Del Norte
Added in 1861 - Mono, Lake
Added in 1864 - Lassen, Alpine
Added in 1866 - Inyo, Kern
Added in 1872 - Ventura
Added in 1874 - San Benito, Modoc
Added in 1889 - Orange
Added in 1891 - Glenn
Added in 1893 Riverside, Kings, Madera
Added in 1907 - Imperial
Charter Counties: Alameda, Butte, El Dorado, Fresno, Los Angeles, Orange, Placer, Sacramento, San Bernardino, San Diego, San Francisco, San Mateo, Santa Clara, Tehama
Charter Versus General Law Counties
The California Constitution of 1879 established a senate with a membership of 40 districts.
Up until 1965 Senatorial Districts were predominately counties.