The Californias Las Californias
Region ofNorth America
Country	Mexico United States
U.S. state	California
Mexican states	Baja California Baja California Sur
Principal cities	List Los Angeles,CA San Diego,CA Monterey,CA San Jose,CA San Francisco,CA Tijuana,BC Mexicali,BC La Paz,BCS Los Cabos,BCS
Area
• Total	569,329 km2 (219,819 sq mi)
Population
• Total	43,636,740
• Density	77/km2 (200/sq mi)
Time zones	UTC-8 (Pacific Standard Time)
• Summer (DST)	UTC-7 (Pacific Daylight Time)
	UTC-7 (Mountain Standard Time)
• Summer (DST)	UTC-6 (Mountain Daylight Time)

The Californias (Spanish:Las Californias), occasionally known as theThree Californias^[1][2][3][4] or theTwo Californias,^[5][6][7] are aregion ofNorth America spanning theUnited States andMexico, consisting of theU.S. state ofCalifornia and theMexican states ofBaja California andBaja California Sur.^{[8][9][10][11]} Historically, the termLas Californias was used to define the vast northwestern region ofSpanish America, as theProvince of the Californias (Spanish:Provincia de las Californias), and later as a collective term forAlta California and theBaja California peninsula.^[12][13]

Originally a single, vast entity within theSpanish Empire, administration was split into Baja California (Lower California) and Alta California (Upper California) following theMexican War of Independence. As a part of theMexican–American War (1846–48), theConquest of California saw the vast Alta California territory ceded from Mexico to the United States. The populated coastal region of the territory wasadmitted into the Union in 1850 as theState of California, while the vast, sparsely populated interior region would only later gain statehood asNevada,Utah, and parts ofNew Mexico,Arizona,Wyoming, andColorado.

Today, "the Californias" is a collective term to refer to the American and Mexican states bearing thename California, which share geography, history, cultures, and strong economic ties.^[14][15] TheCommission of the Californias is a tri-lateral forum for cooperation between the three Californian state governments.^[16]

There has been understandable confusion about use of the pluralCalifornias by Spanish colonial authorities. California historianTheodore Hittell offered the following explanation:

In very early times, while the country was supposed to be an island or rather several islands, it was commonly known by the plural appellation of "Las Californias" (The Californias). Afterwards, when its peninsular character was ascertained, it was called simply California; but the territory so designated was unlimited in extent. When the expeditions for the settlement of San Diego and Monterey marched, it was understood that they were going, not out of California, but into a new part of it. The peninsula then began to be generally spoken of as Antigua or Old California and the unlimited remainder as Nueva or New California, subsequently more commonly called Alta or Upper California. At the same time the old plural name of The Californias was revived, but with a more definite signification than before.^[17]

The first attempted Spanish occupation of California was by the Jesuit missionaryEusebio Kino, in 1683. HisMisión San Bruno failed, however, and it was not until 1697 thatMisión de Nuestra Señora de Loreto Conchó was successfully established by another Jesuit,Juan María de Salvatierra. The mission became the nucleus ofLoreto, first permanent settlement and first administrative center of the province. The Jesuits went on to found a total of18 missions in the lower two-thirds of theBaja California Peninsula.

In 1767, theJesuits were expelled from the missions, and Franciscans were brought in to take over.Gaspar de Portolá was appointed governor to supervise the transition. At the same time, a newvisitador,José de Gálvez, was dispatched from Spain with authority to organize and expand the fledgling province.^[18]

The more ambitious province name,Las Californias, was established by a joint dispatch to the King fromViceroy de Croix andvisitador José de Gálvez, dated January 28, 1768. Gálvez sought to make a distinction between theAntigua ('old') area of established settlement and theNueva ('new') unexplored areas to the north. At that time, almost the only explored and settled areas of the province were around the former Jesuit missions but, once exploration and settlement of the northern frontier began in earnest, the geographical designationsAlta ('upper') andBaja ('lower') gained favor.

The single province was divided in 1804, intoAlta California province and Baja California province.^[19] By the time of the 1804 split, theAlta province had expanded to include coastal areas as far north as what is now theSan Francisco Bay Area in theU.S. state ofCalifornia. Expansion came through exploration and colonization expeditions led byPortolá (1769), his successorPedro Fages (1770),Juan Bautista de Anza (1774–76), the Franciscan missionaries and others. The capital of Alta California wasMonterey. Independent Mexico retained the division but demoted the former provinces to territories, due to populations too small for statehood.

Department of the Californias Departamento de las Californias
Department of theMexican Republic
1836–1847
Seal
Capital	Loreto,Ensenada,Pueblo de Los Angeles, &Monterey
Demonym	Californio
History
• Established	1836
• Disestablished	1847
Preceded by Succeeded by Alta California Baja California Territory California Republic Mexican Cession Baja California Territory
Today part of	California Baja California Baja California Sur Nevada Arizona Utah Wyoming

In 1836, the designationLas Californias was revived, reuniting Alta and Baja California into a singledepartamento (department) as part of the conservative government reforms codified in theSiete Leyes (Seven Laws). The Seven Laws were repealed in 1847, during theMexican–American War, and the split of the two Californias was restored.

Following Mexico's defeat in the war, most of the former Alta California territory was ceded on 2 February 1848 to the United States, under the terms of theTreaty of Guadalupe Hidalgo. The newMexico–United States border was established slightly to the north of the previous Alta-Baja border, and the termsLas Californias andAlta California were no longer formally used. The areas acquired by the U.S. remained under military authority, pending creation of civilian government through territorial designation and/or statehood.

Baja California in Mexico was established as theBaja California Territory after the War. It was split by the Congress into Northern and Southern territories. Seven new U.S. states were created entirely or partly from land formerly included in the Californias.

1850. California became the 31st of the United States.
1853. TheGadsden Purchase transferred additional territory from Mexico to the United States.
1853.William Walker led a force that attempted to capture the Baja California Territory andSonora to create an independentRepublic of Sonora. Walker was defeated by Mexican forces led byAntonio Meléndrez.
1864. Nevada became the 36th of the United States.
1876. Colorado became the 38th of the United States.
1890. Wyoming became the 44th of the United States.
1896. Utah became the 45th of the United States.
1912. New Mexico became the 47th of the United States.
1912. Arizona became the 48th of the United States.
1931. Baja California Territory was divided into theTerritory of Baja California Norte and theTerritory of Baja California Sur.
1952. The Territory of Baja California Norte became the 29th State of Mexico asBaja California.
1984.Baja California Sur became a Mexican state.^[20]

The Baja California Peninsula is bordered on three sides by water, thePacific Ocean (south and west) andGulf of California (east); while Alta California had the Pacific Ocean on the west and deserts on the east. A northern boundary was established by theAdams–Onís Treaty of 1819. That boundary line remains the northern boundary of the U.S. states of California, Nevada, and the western part of Utah.

Inland regions were mostly unexplored by the Spanish, leaving them generally outside the control of the colonial authorities.Mountain ranges of thePeninsular Ranges, easternTransverse Ranges, and theSierra Nevada, along with the aridColorado Desert,Mojave Desert, andGreat Basin Desert in their easternrain shadows, served as natural barriers to Spanish settlement. The eastern border of upper Las Californias was never officially defined under either Spanish or subsequent Mexican rule.^[23] The 1781Instrucciones and government correspondence described Alta California ("Upper California") as the areas to the west of theSierra Nevada and the lower part of theColorado River in theLower Colorado River Valley (the river forms the present day border between the states of California and Arizona).^[24]

• Spanish missions in Baja California
• Spanish missions in California
• Indigenous peoples of California
  • Population of Native California
  • Indigenous peoples of Baja California
• Ranchos of California
• History of California
  • History of California through 1899
  • Territorial evolution of California
• Spanish colonization of the Americas
• The Canadas
• The Carolinas
• The Dakotas
• The Floridas
• The Virginias

Wikimedia Commons has media related toThe Californias.

• Worldstatesmen.org: Provinces of New Spain

• States and territories established in 1836
• States and territories disestablished in 1847
• The Californias
• Regions of North America
• Former Spanish colonies
• New Spain
• Colonial Mexico
• Colonial United States (Spanish)
• Spanish colonization of the Americas
• History of Baja California
• History of Baja California Sur
• Pre-statehood history of California
• Pre-statehood history of Nevada
• Pre-statehood history of Utah
• Historical geography of Mexico
• History of the Gulf of California

• CS1 Spanish-language sources (es)
• Articles with short description
• Short description matches Wikidata
• Short description is different from Wikidata
• Pages using infobox settlement with no coordinates
• Articles containing Spanish-language text
• Pages using largest cities with unknown parameters
• Commons category link from Wikidata