Santa Ana is the most populous city in Orange County, California and is the county seat. It lies approximately 10 miles inland from the Pacific Ocean, on the largely seasonal Santa Ana River. The Santa Ana Freeway (Interstate 5) runs through the city, and the Costa Mesa Freeway (55 Freeway) and Garden Grove Freeway (22 Freeway) travel along its edges. It is today best-known for its enormous Hispanic population, now comprising over 75% of what was once a virtually all-white city. It has the highest percentage of Latinos among the 50 largest cities in America. The current OMB metropolitan designation for Santa Ana and the Orange County Area is "Santa Ana-Anaheim-Irvine, CA."
Members of the Tongva and Juaneño/Luiseño nations long inhabited the area. After the 1769 expedition of Gaspar de Portolà, a Spanish expedition led by Father Junipero Serra named the area Vallejo de Santa Ana (Valley of Saint Anne). On November 1, 1776, Mission San Juan Capistrano became the areas first permanent European settlement in Alta California, New Spain.
In 1801, the Spanish Empire granted 62,500 acres to Jose Antonio Yorba, which he named Rancho San Antonio. Yorba's great rancho included the lands where the cities of Olive, Orange, Irvine, Villa Park, Santa Ana, Tustin, Costa Mesa and Newport Beach stand today.
Claimed in 1869 by Kentuckian William H. Spurgeon on land obtained from the descendents of Jose Antonio Yorba, Santa Ana was incorporated as a city in 1886 with a population of 2000 and in 1889 became the seat of the newly formed Orange County.
One of Santa Ana's most notable businesses is the Rickenbacker musical instrument company, whose electric guitars and bass guitars earned fame in the hands of many rock and roll legends. Santa Ana is also the home of the First American Corporation and Ingram Micro, and the original Glenn L. Martin aviation company, which later merged with the Lockheed Corporation to form the largest aircraft and weapons manufacturing corporation on the planet, Lockheed Martin.
Santa Ana is home to Santa Ana College, a community college that is part of the Rancho Santiago Community College District. Mater Dei High School, Valley High School, Middle College High School, Santa Ana High School, Saddleback High School, Century High School, Segerstrom Fundamental High School, newly opened Godinez Fundamental High School and other major schools in the area, along with the Orange County High School of the Arts in the downtown district. It also is home to one of the many post-secondary private Art Institutions of California.
Santa Ana Unified School District includes thirty-seven K-5 elementary schools, nine 6-8 intermediate schools, eight 9-12 high schools, five special schools, and one charter school. The school district provides an online accountability report card, viewable at this url address: http://www.sausd.k12.ca.us/departments/research_eval/accountability.asp
The Roman Catholic Diocesan K-8 schools available in Santa Ana are: School of Our Lady, Saint Anne, Saint Barbara, and Saint Joseph. (Immaculate Heart Of Mary And Our Lady Of the Pillar schools were closed in 2005 and merged into the School of Our Lady which is located at Immaculate Heart of Mary Parish. 
As of the censusGR2 of 2000, there were 337,977 people, 73,002 households, and 59,788 families residing in the city. The population density was 4,808.2/km² (12,451.9/mi²). There were 74,588 housing units at an average density of 1,061.1/km² (2,748.0/mi²). Some consider these numbers to be severely undercounted, and put the population, which may consist of up to 25% undocumented migrants, at 500,000.  Santa Ana's population density is 4.6 per housing unit, the highest of any American city over 50,000. (By contrast, New York's is 2.8, and Los Angeles's density is 2.6 persons per housing unit.) Many residents live in illegally converted garages or in rooms not meant for occupancy. The city has attempted to reduce the number of individuals living inside one house by passing density limitations, which resulted in a civil rights lawsuit being filed and the limits ultimately dropped. 
The racial makeup of the city was 42.73% White, 1.70% African American, 1.19% Native American, 8.81% Asian, 0.34% Pacific Islander, 40.64% from other races, and 4.58% from two or more races. Hispanic or Latino of any race were 76.07% of the population. Non-Hispanic Whites make up 12.4% of the population, a small fraction of what was a majority in 1950 and 1960.
There were 73,002 households out of which 53.2% had children under the age of 18 living with them, 60.6% were married couples living together, 13.5% had a female householder with no husband present, and 18.1% were non-families. 12.7% of all households were made up of individuals and 4.6% had someone living alone who was 65 years of age or older. The average household size was 4.55 and the average family size was 4.72.
In the city the population was spread out with 34.2% under the age of 18, 12.8% from 18 to 24, 34.1% from 25 to 44, 13.5% from 45 to 64, and 5.5% who were 65 years of age or older. The median age was 26 years. For every 100 females there were 107.7 males. For every 100 females age 18 and over, there were 108.7 males. Santa Ana bucks the national trend on a large percentage of young people under the age of 21.
The median income for a household in the city was $43,412, and the median income for a family was $41,050. Males had a median income of $23,342 versus $21,637 for females. The per capita income for the city was $12,152. About 16.1% of families and 19.8% of the population were below the poverty line, including 24.1% of those under age 18 and 10.4% of those age 65 or over. Santa Ana is a city divided by socio-economic class stratification after decades of immigration and economic prosperity.
The reason for Santa Ana's appeal to a large Hispanic immigrant population since the 1970s was its proximity to rich job markets, the cost of cheap housing until recently, the availability of multi-housing units dating back before the Orange County suburban boom, and a history of Mexican American culture is appealing to immigrants closely attached to Mexico. In 1970 (U.S. Census) the city's Hispanic percentage was 30 percent, then increased to 53 percent in 1980 and went up to 65 percent by 1990. Santa Ana has a large presence (compared to Orange county) of African Americans. Also large numbers of Asian Americans and Middle Easterners, such as Iranians, Indian Americans and Vietnamese Americans arrived in Santa Ana during the 1980s.
Santa Ana is home to:
The Rancho Santiago Community College District, established in 1878, has six satellite campus locations across Orange County, including Santa Ana College.
Greenville, a formerly rural section of Santa Ana, has buildings over a century-old, but industrial complexes replaced agricultural fields that once surrounded the town.
Santa Ana has several wall paintings and murals depicting local history, community events and cultural diversity in Orange County.