The history ofOrange County begins withAcjachemen indigenous peoples who lived sustainably off the land. Spanish colonization starting in this area around 1769 introduced missions and ranchos, which later transitioned to American control afterCalifornia joined theUnited States following its gold rush in 1848. The gold rush and railroads spurred economic and population growth throughout the state, leading to the founding of towns likeAnaheim and Santa Ana.

In 1889, Orange County separated from Los Angeles County. Agriculture, especially citrus, dominated until the mid-20th century, alongside oil and transportation development. After World War II, suburban expansion replaced farmland, and cities rapidly grew. The 1955 opening ofDisneyland marked a shift toward tourism. Today, Orange County is a major urban center with over three million residents and 34 cities.

Archeological evidence shows the area to have been inhabited beginning about 9,500 years ago.[2] At the time of European contact, the northern area of what is now Orange County was primarily inhabited by theTongvaindigenous people, a part ofTovaangar, while the southern area of the county, belowAliso Creek, was primarily inhabited by theAcjachemen.[3][4] Both groups lived in villages throughout the area. Large villages were sometimesmultiethnic andmultilingual, such asGenga, located in what is nowNewport Beach. The village was shared by the Tongva and Acjachemen.[5] The village ofPuhú was located in what is nowBlack Star Canyon and was shared by multiple groups, including the Tongva, Acjachemen,Serrano andPayómkawichum.[6]
The mother village of theAcjachemen wasPutuidem and is now located inSan Juan Capistrano underneathJSerra Catholic High School.[7][8] For theTongva, north Orange County was at the southern extent of their village sites.[9] In coastal villages likeLupukngna, at least 3,000 years old located in what is nowHuntington Beach, villagers likely usedte'aats or plank boats to navigate the coastline, with fish and shellfish being more central to the diet.[10][11] In inland villages such asHutuknga, rabbit andmule deer were more central, in addition to acorns fromoak trees and seeds from grasses and sage bushes common everywhere.[12]

After the 1769 expedition ofGaspar de Portolà, a Spanish expedition led byJunipero Serra named the area Valle de Santa Ana (Valley ofSaint Anne).[14] On November 1, 1776,Mission San Juan Capistrano became the area's first permanent European settlement. Among those who came with Portolá wereJosé Manuel Nieto andJosé Antonio Yorba. Both these men were given land grants—Rancho Los Nietos andRancho Santiago de Santa Ana, respectively.[15]
The Nieto heirs were granted land in 1834. The Nieto ranches were known asRancho Los Alamitos,Rancho Las Bolsas, andRancho Los Coyotes. Yorba heirsBernardo Yorba andTeodosio Yorba were also grantedRancho Cañón de Santa Ana (Santa Ana Canyon Ranch) andRancho Lomas de Santiago, respectively. Other ranchos in Orange County were granted by the Mexican government during the Mexican period inAlta California.[15]
SaintJunípero Serra y Ferrer and the early components of thePortolá Expedition arrived in modern-daySan Diego, south of present-day Orange County, in mid-late 1769. During these earlyMission years, however, the early immigrants continued to rely on imports of bothMexican-grown andSpanish-grown wines; Serra repeatedly complained of the process of repeated, labored import.[16] The first grape crop production was produced in 1782 atSan Juan Capistrano, with vines potentially brought through supply ships in 1778.[16]
Viticulture became an increasingly important crop inLos Angeles and Orange Counties through the subsequent decades. By the 1850s, the regions supported more than 100vineyards.[17] In 1857,Anaheim was founded by 50German-Americans (with lineage extending back toFranconia) in search of a suitable grape-growing region.[18] This group purchased a 1,165 acres (4.71 km2) parcel from Juan Pacifico Ontiveros's Rancho San Juan Cajon de Santa Ana for $2 per acre and later formed theAnaheim Vineyard Company.[19][17] With surveyorGeorge Hansen, two of the wine colony's founders, John Frohling and Charles Kohler, planted 400,000grapevines along theSanta Ana River; by 1875, "there were as many as 50wineries in Anaheim, and the city's wine production topped 1 million gallons annually."[17] Despite later afflictions of bothPhylloxera andPierce's Disease, wine growing is still practiced.[20]
A severe drought in the 1860s devastated the prevailing industry,cattleranching, and much land came into the possession of Richard O'Neill Sr.,[21]James Irvine and otherland barons. In 1887,silver was discovered in theSanta Ana Mountains, attracting settlers via theSanta Fe andSouthern Pacific Railroads. High rates of Anglo migration gradually moved Mexicans intocolonias, or segregatedethnic enclaves.[22]

After several failed attempts in previous sessions, theCalifornia State Legislature passed a bill authorizing the portion ofLos Angeles County south ofCoyote Creek to hold a referendum on whether to remain part of Los Angeles County or to secede and form a new county to be named "Orange" as directed by the legislature. The county is said to have been named for thecitrus fruit in an attempt to promote immigration by suggesting a semi-tropical paradise – a place where anything could grow.[23] James William Towner, a large landowner in Santa Ana and former member of theOneida Community, was appointed by the then governor to hold the referendum.[24] The referendum required a 2/3 vote for secession to take place, and on June 4, 1889, the vote was 2,509 to 500 in favor of secession. After the referendum, Los Angeles County filed three lawsuits to prevent the secession,[citation needed] but their attempts were futile.[citation needed]
On July 17, 1889, a second referendum was held south of the Coyote Creek to determine if the county seat of the new county would be Anaheim or Santa Ana, along with an election for every county officer. Santa Ana defeated Anaheim in the referendum. With the referendum having passed, the County of Orange was officially incorporated on August 1, 1889.[25] Much of the land around the future county courthouse were owned by members of the Oneida Community, and Towner would become the county's first Superior Court judge.[26] Since the incorporation of the county, the only geographical changes made to the boundary was when the County and Los Angeles County traded some parcels of land around Coyote Creek to conform to city blocks.[when?] In 1919, the California State Legislature redefined the county's boundary with Los Angeles County to no longer follow Coyote Creek but instead alongPublic Land Survey System township lines instead.[27]

Other citrus crops,avocados, andoil extraction were also important to the early economy. Orange County benefited from the July 4, 1904, completion of thePacific Electric Railway, atrolley connectingLos Angeles with Santa Ana andNewport Beach. The link made Orange County an accessible weekend retreat for celebrities of earlyHollywood. It was deemed so significant that Pacific City changed its name toHuntington Beach in honor ofHenry E. Huntington, president of the Pacific Electric and nephew ofCollis Huntington. Transportation further improved with the completion of the State Route andU.S. Route 101 (now mostlyInterstate 5) in the 1920s.

In the 1910s, agriculture in Orange County was largely centered on grains, hay, and potatoes by small farmers, accounting for 60% of the county's exports. TheSegerstroms and Irvines once produced so manylima beans that the county was called "Beanville".[28] By 1920, fruit and nut exports exploded, which led to the increase of industrialized farming and the decline of family farms. For example, by 1917, William Chapman came to own 350,000 acres in northeastern Orange County from theValencia orange.[29] Around the 1910s and 1920s, most of thebarrios of Orange County, such as in Santa Ana, further developed ascompany towns of Mexican laborers, who worked in the industrial orange groves.[30] Poor working conditions resulted in theCitrus Strike of 1936, in which more than half of the orange industry's workforce, largely Mexican, demanded better working conditions. The strike was heavily repressed, with forced evictions and state-sanctioned violence being used as tactics of suppression.[31]Carey McWilliams referred to the suppression as "the toughest violation of civil rights in the nation."[22]
TheLos Angeles flood of 1938 devastated some areas of Orange County, with most of the effects being in Santa Ana and Anaheim, which were flooded with six feet of water. As an eight-foot-high rush of water further spilled out of theSanta Ana Canyon, forty-three people were killed in the predominately Mexican communities ofAtwood andLa Jolla inPlacentia.[32] The devastation from this event, as well as from the1939 California tropical storm, meant that Orange County was in need of new infrastructure, which was supported by theNew Deal. This included the construction of numerous schools, city halls, post offices, parks, libraries, and fire stations, as well as the improvement of road infrastructure throughout Orange County.[33]

School segregation between Mexican and white students in Orange County was widespread in the mid-1940s, with 80% of Mexican students attending 14 segregated schools. These schools taught Mexican children manual education – orgardening,bootmaking,blacksmithing, andcarpentry for Mexican boys and sewing and homemaking for girls – while white schools taught academic preparation.[34] The landmark caseMendez vs. Westminster (1947) desegregated Orange County schools, after the Mendez family were denied enrollment into the17th Street School inWestminster in 1944, despite their cousins with lighter skin being admitted, and were instead told to enroll at theHoover Elementary School for Mexican children.[35]
In the 1950s, agriculture, such as that involving theboysenberries made famous byBuena Park nativeWalter Knott, began to decline. However, the county's prosperity soared during this time. The completion ofInterstate 5 in 1954 helped make Orange County abedroom community for many who moved toSouthern California to work inaerospace and manufacturing.[36] Orange County received a further economic boost in 1955 with the opening ofDisneyland.
In 1969,Yorba Linda-born Orange County nativeRichard Nixon became the 37thPresident of the United States. He established a "Western White House" inSan Clemente, in South Orange County, known asLa Casa Pacifica, and visited throughout his presidency.[37]
In the late 1970s, Vietnamese and Latino immigrants began to populate central Orange County.[38]
In the 1980s, Orange County had become the second most populous county in California as the population topped two million for the first time.[citation needed]
In the 1990s,red foxes became common in Orange County as a non-nativemesopredator, with increasing urban development pushing out coyote and mountain lion populations to the county's shrinking natural areas.[39][40]
In 1994, an investment fund meltdown led to the criminal prosecution of treasurerRobert Citron. The county lost at least $1.5 billion through high-risk investments in bonds. The loss was blamed onderivatives by some media reports.[41] On December 6, 1994, the County of Orange declaredChapter 9 bankruptcy,[41] from which it emerged on June 12, 1996.[42] The Orange County bankruptcy was at the time the largest municipal bankruptcy in U.S. history.[41]
Land use conflicts arose between established areas in the north and less developed areas in the south. These conflicts were over issues such as construction of new toll roads and the repurposing of a decommissioned air base.El Toro Marine Corps Air Station was designated by a voter measure in 1994 to be developed into an international airport to complement the existingJohn Wayne Airport. But subsequent voter initiatives and court actions caused the airport plan to be permanently shelved. It has developed into theOrange County Great Park and housing.[43]
In the 21st century, the social landscape of Orange County has continued to change. Theopioid epidemic saw a rise in Orange County, with unintentional overdoses becoming the third highest contributor of deaths by 2014. As in other areas, the deaths disproportionately occurred in thehomeless population. However, deaths were widespread among affluent and poorer areas in Orange County, with the highest at-risk group being Caucasian males between the ages of 45–55. A 2018 study found that supply reduction was not sufficient to preventing deaths.[44]
In 2008, a report issued by theOrange County Superior Court found that the county was experiencing a pet "overpopulation problem," with the growing number of pets leading to an increase ineuthanasias at the Orange County Animal Shelter to 13,000 for the year alone.[45]
Following the2016 presidential election, Santa Ana become asanctuary city for the protection of those immigrants who worked around the legally established process of becoming a legal resident in Orange and other California counties. This created an intense debate in Orange County surrounding politics toward unlawful immigration, with many cities opposing pro-immigration policies.[46]
TheCOVID-19 pandemic in Orange County disproportionately affected lower income and Latino residents.[47]
Implementation ofrenewable energy andclimate change awareness in Orange County increased, with the city of Irvine pledging to be azero-carbon economy by 2030 andBuena Park,Huntington Beach, andFullerton pledging to move to 100% clean energy.[48] Residential solar panel installation has rapidly increased, even among middle-income families, as a result of the state's residential solar program which began in 2006.
In the 2010s, campaigns to conserve remaining natural areas gained awareness.[49][50] By the early 2020s, some success was found, with the conservation of 24 acres in theWest Coyote Hills of a total 510 acres and the Genga/Banning Ranch project moving forward, conserving some 385 acres, which was part of theTongva village area ofGenga.[49][50][51] In 2021, the commemorative 1.5 acrePutuidem village opened after years of delays and campaigning by theAcjachemen.[52]
{{cite book}}: CS1 maint: location missing publisher (link){{cite book}}: CS1 maint: location missing publisher (link){{cite book}}: CS1 maint: others (link){{cite book}}: CS1 maint: location missing publisher (link){{cite book}}:ISBN / Date incompatibility (help){{cite book}}: CS1 maint: location missing publisher (link){{cite book}}: CS1 maint: location missing publisher (link){{cite book}}: CS1 maint: location missing publisher (link)Vietnamese and Latinos, mostly of Mexican descent, began populating the starter tracts of Central Orange County in the late 1970s and early '80s—the Vietnamese fleeing the Communist government after the war and Latinos looking for better economic opportunities. Vietnamese at first settled largely in Westminster and Latinos in Santa Ana.