Southern California

==Northern boundary==
[[File:Southern California.png|thumb|upright=1.35|right|California counties below the 36th [[standard parallel]]]]
Southern California is generally considered the area of California south of the latitude 35°45',<ref>{{cite book |title=Pacific Summary / Index: June 1, 1986 – July 31, 1987 |series=Outer Continental Shelf Oil & Gas Activities |author=[[Minerals Management Service]] |date=1987 |publisher=[[U.S. Department of the Interior]] |page=6 |url=https://books.google.com/books?id=CSJPAAAAMAAJ&pg=PA6 |access-date=February 21, 2023 |archive-date=February 21, 2023 |archive-url=https://web.archive.org/web/20230221022446/https://books.google.com/books?id=CSJPAAAAMAAJ&pg=PA6 |url-status=live }}</ref> approximately one-third of the state, formed by the northern boundaries of [[San Luis Obispo County, California|San Luis Obispo]], [[Kern County, California|Kern]], and [[San Bernardino County, California|San Bernardino]] counties, which are not exactly a straight line. Another definition for Southern California uses [[Point Conception]] and the [[Tehachapi Mountains]] as the northern geographical barriers, especially when defining California's [[bioregion]]s.<ref>{{Cite news |last=Smith |first=Thomas |date=2023-04-23 |title=Where Does Southern California Stop and Northern California Start? |url=https://bayareatelegraph.com/2023/04/23/where-does-southern-california-stop-and-northern-california-start/ |access-date=2023-04-25 |work=Bay Area Telegraph |language=en-US}}</ref><ref>{{cite book |url=https://books.google.com/books?id=dF4KBAAAQBAJ&pg=PA265 |page=265 |editor1=Cheryll Glotfelty |editor2=Eve Quesnel |title=The Biosphere and the Bioregion: Essential Writings of Peter Berg |author=Peter Berg |date=2014 |publisher=Routledge |isbn=9781134504091}}</ref>

[[File:Wpdms shdrlfi020l tehachapi mountains.jpg|thumb|upright=1.35|Topography of the border region]]
Following the acquisition of the territory of California by the United States, several pro-slavery politicians attempted to arrange the division of Alta California at 36 degrees, 30 minutes, the [[Missouri Compromise line|line of the Missouri Compromise]]. Instead, the passing of the [[Compromise of 1850]] enabled California to be admitted to the Union as a [[Slave and free states|free state]], preventing the southern half California from becoming its own separate [[slave state]].

Subsequently, Californians (dissatisfied with inequitable taxes and land laws) and pro-slavery Southerners in the lightly populated "cow counties" of Southern California attempted three times in the 1850s to achieve a separate statehood or territorial status [[Partition and secession in California|separate from Northern California]]. The last attempt, the Pico Act of 1859, was passed by the [[California State Legislature]] and signed by State Governor [[John B. Weller]]. It was approved overwhelmingly by nearly 75 percent of voters to form the proposed [[Territory of Colorado (California)|Territory of Colorado]]. This territory was to include a portion of the much larger [[Tulare County]] and all of [[San Luis Obispo County]]. The proposal was sent to [[Washington, D.C.]], with a strong advocate in Senator [[Milton Latham]]. However, the secession crisis following the [[U.S. presidential election, 1860|election]] of [[Abraham Lincoln]] in 1860 and the subsequent [[American Civil War]] led to the proposal never coming to a vote.<ref>{{cite book|last1=DiLeo|first1=Michael|last2=Smith|first2=Eleanor|year=1983|title=Two Californias: The Myths And Realities of a State Divided Against Itself|publisher=Island Press|location=Covelo, California|url=https://books.google.com/books?id=OEqiYRm-ohMC&pg=PA27|isbn=978-0-93328-016-8|page=30|access-date=May 9, 2021|archive-date=March 15, 2023|archive-url=https://web.archive.org/web/20230315184920/https://books.google.com/books?id=OEqiYRm-ohMC&pg=PA27|url-status=live}}</ref><ref>{{cite book|last=California|first=Historical Society of Southern|year=1901|title=The Quarterly, Volumes 5-6|publisher=Historical Society of Southern California|url=https://books.google.com/books?id=WCMLAAAAIAAJ&pg=PA223|page=223|access-date=May 9, 2021|archive-date=March 15, 2023|archive-url=https://web.archive.org/web/20230315184948/https://books.google.com/books?id=WCMLAAAAIAAJ&pg=PA223|url-status=live}}</ref>

In 1900, the ''[[Los Angeles Times]]'' defined Southern California as including "the seven counties of Los Angeles, San Bernardino, Orange, Riverside, San Diego, Ventura and Santa Barbara." This definition left out San Luis Obispo and Kern counties.<ref>{{cite news|url=https://articles.latimes.com/1999/dec/31/news/cl-49174|title=L.A. Then AND NOW|newspaper=Los Angeles Times|date=December 31, 1999|last=Bernstein|first=Leilah|access-date=February 27, 2017|url-status=live|archive-url=https://archive.today/20170227180649/http://articles.latimes.com/1999/dec/31/news/cl-49174|archive-date=February 27, 2017}}</ref>

Southern California was the name of a [[Cal 3|proposed new state]] which failed to get on the 2018 California ballot. The ballot measure proposed splitting the existing state into three parts.<ref>{{cite news|url=https://www.latimes.com/politics/la-pol-ca-california-split-three-states-20180612-story.html|title=Radical plan to split California into three states earns spot on November ballot|newspaper=Los Angeles Times|date=June 13, 2018|last=Myers|first=John|access-date=June 14, 2018|url-status=live|archive-url=https://web.archive.org/web/20200225170640/https://www.latimes.com/politics/la-pol-ca-california-split-three-states-20180612-story.html|archive-date=February 25, 2020}}</ref>

In December 2020, during the [[COVID-19 pandemic]], the state government led by Governor [[Gavin Newsom]] divided the state into five regions for the purpose of issuing stay-at-home orders. The Southern California region consists of the following counties: [[Imperial County, California|Imperial]], [[Los Angeles County, California|Los Angeles]], [[Kern County, California|Kern]], [[Orange County, California|Orange]], [[Riverside County, California|Riverside]], [[San Bernardino County, California|San Bernardino]], [[San Diego County, California|San Diego]], [[San Luis Obispo County, California|San Luis Obispo]], [[Santa Barbara County, California|Santa Barbara]] and [[Ventura County, California|Ventura]]. However, Kern County was grouped with other counties of the [[San Joaquin Valley]], California's central agricultural valley.<ref>{{cite web|url=https://www.gov.ca.gov/2020/12/03/california-health-officials-announce-a-regional-stay-at-home-order-triggered-by-icu-capacity/|title=California Health Officials Announce a Regional Stay at Home Order Triggered by ICU Capacity|publisher=State of California|date=2020-12-03|access-date=2020-12-30|archive-date=March 27, 2021|archive-url=https://web.archive.org/web/20210327144757/https://www.gov.ca.gov/2020/12/03/california-health-officials-announce-a-regional-stay-at-home-order-triggered-by-icu-capacity/|url-status=live}}</ref>

{| style="font-size:95%; text-align:right;" class="wikitable sortable"
|+Population, land area & population density (2020)
!County<br /><small>[[#References|Ref.]]</small>
!Population
!Land<br />mi{{sup|2}}<ref name="auto">{{cite web |title=Counties |url=https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.2020.html |website=2020 U.S. Census Gazetteer Files |publisher=United States Census Bureau |access-date=September 3, 2021 |archive-date=October 26, 2021 |archive-url=https://web.archive.org/web/20211026060851/https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.2020.html |url-status=live }}</ref>
!Land<br />km{{sup|2}}
!Pop.<br />/mi{{sup|2}}
!Pop.<br />/km{{sup|2}}
|-
|align=left|[[Los Angeles County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/losangelescountycalifornia,US/PST045219|title=Los Angeles County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021|archive-date=May 18, 2021|archive-url=https://web.archive.org/web/20210518091537/https://www.census.gov/quickfacts/fact/table/losangelescountycalifornia,US/PST045219|url-status=live}}</ref>
|{{Nts|10014009}}||{{convert|4059.28|sqmi|km2|2|disp=table|sortable=on}}||{{convert|2466.94|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[San Diego County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/sandiegocountycalifornia,US/PST045219|title=San Diego County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021|archive-date=September 24, 2021|archive-url=https://web.archive.org/web/20210924205247/https://www.census.gov/quickfacts/fact/table/sandiegocountycalifornia,US/PST045219|url-status=live}}</ref>
|{{Nts|3298634}}||{{convert|4210.23|sqmi|km2|2|disp=table|sortable=on}}||{{convert|783.48|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[Orange County, California|Orange County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/orangecountycalifornia,US/PST045219|title=Orange County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021|archive-date=January 28, 2021|archive-url=https://web.archive.org/web/20210128163939/https://www.census.gov/quickfacts/fact/table/orangecountycalifornia,US/PST045219|url-status=live}}</ref>
|{{Nts|3186989}}||{{convert|792.84|sqmi|km2|2|disp=table|sortable=on}}||{{convert|4019.71|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[Riverside County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/riversidecountycalifornia,US/PST045219|title=Riverside County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021|archive-date=February 1, 2021|archive-url=https://web.archive.org/web/20210201070212/https://www.census.gov/quickfacts/fact/table/riversidecountycalifornia,US/PST045219|url-status=live}}</ref>
|{{Nts|2418185}}||{{convert|7209.27|sqmi|km2|2|disp=table|sortable=on}}||{{convert|335.43|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[San Bernardino County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/sanbernardinocountycalifornia,US/PST045219|title=San Bernardino County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021|archive-date=January 18, 2021|archive-url=https://web.archive.org/web/20210118143307/https://www.census.gov/quickfacts/fact/table/sanbernardinocountycalifornia,US/PST045219|url-status=live}}</ref>
|{{Nts|2181654}}||{{convert|20068.01|sqmi|km2|2|disp=table|sortable=on}}||{{convert|108.71|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[Kern County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/kerncountycalifornia,US/PST045219|title=Kern County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021}}</ref>
|{{Nts|909235}}||{{convert|8134.65|sqmi|km2|2|disp=table|sortable=on}}||{{convert|111.77|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[Ventura County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/venturacountycalifornia,US/PST045219|title=Ventura County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021|archive-date=March 8, 2021|archive-url=https://web.archive.org/web/20210308035312/https://www.census.gov/quickfacts/fact/table/venturacountycalifornia,US/PST045219|url-status=live}}</ref>
|{{Nts|843843}}||{{convert|1840.79|sqmi|km2|2|disp=table|sortable=on}}||{{convert|458.41|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[Santa Barbara County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/santabarbaracountycalifornia,US/PST045219|title=Santa Barbara County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021}}</ref>
|{{Nts|448229}}||{{convert|2733.94|sqmi|km2|2|disp=table|sortable=on}}||{{convert|163.95|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[San Luis Obispo County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/sanluisobispocountycalifornia,US/PST045219|title=San Luis Obispo County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021}}</ref>
|{{Nts|282424}}||{{convert|3300.85|sqmi|km2|2|disp=table|sortable=on}}||{{convert|85.56|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|[[Imperial County]]<ref>{{cite web|url=https://www.census.gov/quickfacts/fact/table/imperialcountycalifornia,US/PST045219|title=Imperial County QuickFacts|date=April 1, 2020|publisher=United States Census Bureau|access-date=September 3, 2021}}</ref>
|{{Nts|179702}}||{{convert|4175.54|sqmi|km2|2|disp=table|sortable=on}}|| {{convert|43.04|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|Southern California||{{Nts|23762904}}||{{convert|56525.40|sqmi|km2|2|disp=table|sortable=on}}||{{convert|420.39|/sqmi|/km2|2|disp=table|sortable=on}}
|-
|align=left|California||{{Nts|39538223}}||{{convert|155959.34|sqmi|km2|2|disp=table|sortable=on}}||{{convert|253.52|/sqmi|/km2|2|disp=table|sortable=on}}
|}