The U.S. state of California is divided into 58 counties. Counties are responsible for local services and law enforcement for areas within their borders that are not within incorporated cites, as well as providing local-level courtss.

On January 4, 1850, the California constitutional committee recommended the formation of 18 counties. They were Benicia, Butte, Fremont, Los Angeles, Mariposa, Monterey, Mount Diablo, Oro, Redding, Sacramento, San Diego, San Francisco, San Joaquin, San Jose, San Luis Obispo, Santa Barbara, Sonoma, and Sutter. On April 22, the counties of Branciforte, Calaveras, Coloma, Colusi, Marin, Mendocino, Napa, Trinity, and Yuba were added. Benicia was renamed Solano, Coloma El Dorado, Fremont Yola, Mt. Diablo Contra Costa, San Jose Santa Clara, Oro Tuolumne, and Redding Shasta. One of the first state legislative acts regarding counties was to rename Branciforte County to Santa Cruz, Colusi to Colusa, and Yola to Yolo.

The present number of counties was achieved over time by subdivision of many of the larger counties into smaller ones. The 1850 counties are marked with an asterisk (*).

Table of contents
1 Counties which no longer exist
2 History of county creations and modifications
3 External links

Counties which no longer exist

  • Klamath County was created in 1851 from the northern half of Trinity County, but in 1874 it was divided between Humboldt and Siskiyou counties.
  • Pautah County was created in 1852 out of territory which, the state of California assumed, was to be ceded to it by the United States Congress from territory in what is now the state of Nevada. When the cession never occurred, the state legislature officially abolished the never-created county in 1859.

History of county creations and modifications

  • 1853 - Alameda, from parts of Contra Costa and Santa Clara Counties
  • 1864 - Alpine, from parts of Amador, El Dorado, Calaveras and Tuolumne Counties
  • 1854 - Amador, from parts of Calaveras and El Dorado. Part of the county's territory went to Alpine County in 1864
  • Butte - One of the original counties. Part of the county's territory went to Plumas County in 1854 and to Tehama in 1856
  • Calaveras - One of the original counties. Part of the county's territory went to Amador County in 1854 and to Alpine in 1864
  • Colusa - One of the original counties. Part of the county's territory went to Tehama County in 1856 and to Glenn in [1891
  • Contra Costa - One of the original counties. Part of the county's territory went to Alameda County in 1853
  • 1857 - Del Norte, from parts of Klamath County
  • El Dorado - One of the original counties. Part of the county's territory went to Amador County in 1854 and to Alpine County in 1864
  • 1856 - Fresno, from parts of Mariposa, Merced and Tulare. Part of the county's territory went to Mono County in 1861 and to Madera in 1893
  • 1891 - Glenn, from parts of Colusa
  • 1853 - Humboldt, from parts of Trinity
  • 1907 - Imperial, from parts of San Diego. The most recent county formed.
  • 1866 - Inyo, from parts of Mono and Tulare
  • 1866 - Kern, from parts of Los Angeles and Tulare
  • 1893 - Kings, from parts of Tulare
  • 1851 - Klamath, from parts of Trinity. Part of the county's territory went to Del Norte in 1857
  • 1861 - Lake, from parts of Napa
  • 1864 - Lassen, from parts of Plumas and Shasta
  • Los Angeles - One of the original counties. Parts of the county's territory went to San Bernardino County 1853, Kern in 1866 and Orange in 1889
  • 1893 - Madera, from parts of Fresno
  • Marin - One of the original counties
  • Mariposa - One of the original counties. Part of the county's territory went to Tulare County in 1852, Merced in 1855, Fresno in 1856 and Mono in 1861. Mariposa County was the largest of the state's original counties, but territory that was once part of Mariposa is now in the counties of 12 other counties -- Fresno, Inyo, Kern, Kings, Los Angeles, Madera, Merced, Mono, San Benito, San Bernardino, San Luis Obispo, and Tulare.
  • Mendocino - One of the original counties.
  • 1855 - Merced, from parts of Mariposa. Part of the county's territory went to Fresno in 1856
  • 1855 - Modoc, from parts of Siskiyou
  • 1861 - Mono, from parts of Calaveras, Fresno and Mariposa. Part of the county's territory went to Inyo in 1866
  • Monterey - One of the original counties. Part of the county's territory went to San Benito in 1874
  • Napa - One of the original counties. Part of the county's territory went to Lake in 1861
  • 1851 - Nevada, from parts of Yuba County
  • 1889 - Orange, from parts of Los Angeles County
  • 1851 - Placer, from parts of Sutter and Yuba Counties
  • 1854 - Plumas, from parts of Butte County. Part of the county's territory went to Lassen in 1864
  • Sacramento - One of the original counties
  • 1874 - San Benito, from parts of Monterey County
  • 1853 - San Bernardino, from parts of Los Angeles County. Part of the county's territory went to Riverside in 1893
  • San Diego - One of the original counties. Part of the county's territory went to Riverside in 1893 and to Imperial in 1907
  • San Francisco - One of the original counties. Part of the county's territory went to San Mateo in 1856
  • San Joaquin - One of the original counties
  • San Luis Obispo - One of the original counties
  • 1856 - San Mateo, from part of San Francisco County
  • Santa Barbara - One of the original counties. Part of the county's territory went to Ventura in 1872
  • Santa Clara - One of the original counties. Part of the county's territory went to Alameda in 1853
  • Santa Cruz - One of the original counties
  • Shasta - One of the original counties. Part of the county's territory went to Siskiyou in 1852, to Tehama in 1856 and to Lassen in 1864
  • 1852 - Sierra, from part of Yuba County
  • 1852 - Siskiyou, from parts of Shasta and Klamath. Part of the county's territory went to Modoc in 1855
  • Solano - One of the original counties
  • Sonoma - One of the original counties.
  • 1854 - Stanislaus, from part of Tuolumne
  • Sutter - One of the original counties. Part of the county's territory went to Placer in 1851
  • 1856 - Tehama, from parts of Butte, Colusa and Shasta
  • Trinity - One of the original counties. Part of the county's territory went to Klamath in 1852 and to Humboldt in 1853
  • 1852 - Tulare, from part of Mariposa. Part of the county's territory went to Fresno in 1856, to Kern in 1866, to Inyo in 1866 and to Kings in 1893
  • Tuolumne - One of the original counties. Part of the county's territory went to Stanislaus in 1854 and to Alpine in 1864
  • 1872 - Ventura, from part of Santa Barbara
  • Yolo - One of the original counties
  • Yuba - One of the original counties. Part of the county's territory went to Placer in 1851, to Nevada in 1851 and to Sierra in 1852

External links