World Facts

Most Populous Counties In The United States

According to official US Census Bureau Estimates from 2014, 4 of the top 10 are in California, which is also the most populous state in the U.S.

10. Riverside County, California (2.33 million people)

Riverside County, California covers an area of over 7,000 square miles, and is part of a larger region known as the "Inland Empire". The county includes an array of cities and resort areas, such as Indian Wells, Rancho Mirage, Palm Springs, Coachella, and Canyon Lake. One of the many unique aspects of Riverside County is that it's home to Gold Base, which is the international headquarters of the controversial Church of Scientology. This California county also includes a dozen Native American reservations, as well as a number of abandoned or so called "ghost towns", including one deserted community named Hell.

9. Dallas County, Texas (2.52 million people)

Dallas County, Texas was established in 1846, and includes the cities of Dallas, Fort Worth, and Arlington. This county in the "Lone Star state" garnered international attention after the 1963 assassination of President John F. Kennedy which took place in Dallas. The county is also home to Love Field, the airport where Lyndon B. Johnson was sworn into office aboard Air Force One immediately after the same JFK's death. Dallas County also features attractions such as The Old Red Museum, which chronicles the history of the area beginning with the first white settlements in 1841. Among the artifacts featured in the museum include a mammoth’s tooth, a gas mask from World War I, a gun used by the notorious bank robber Clyde Barrow, as well as a cowboy hat worn by Larry Hagman’s character J.R. on the hit TV show “Dallas”.

8. Kings County, New York (2.62 million people)

Kings County, New York is composed of the same geographical boundaries as the borough of Brooklyn. Citizens living in the county are popularly referred to as Brooklynites, and come from an array of ethnic backgrounds. The county includes a number of ethnically defined neighborhoods, each largely composed of members of their distinctive Chinese, Jewish, Irish, Russian, Italian, Greek, and Pakistani communities. In terms of its historical significance, the county was established in 1634 and founded by Dutch settlers. Brooklyn also played an important role during the US Civil War by supplying troops and military equipment to the Union Army. Kings County’s many attractions include the Coney Island Amusement Park, the Brooklyn Botanical Garden, and Prospect Park.

7. Miami-Dade County, Florida (2.66 million people)

Located in southeastern Florida, Miami-Dade County was founded in 1836 and takes its name from Major Francis L. Dade, who lost his life in the "Dade Massacre" in 1835 during the Second Seminole War. Formerly simply known as Dade County, Miami was added to the county’s name in 1997 in order to capitalize on the popularity and tourism industry of the city of Miami. Miami-Dade County is home to a portion of the Everglades eco-region, as well as the Biscayne National Park. A large portion of the county’s population is composed of Cuban immigrants, as well as those arriving from such other countries as Colombia, Haiti, Honduras, Peru, Jamaica, and Mexico. Languages commonly spoken in the county include Spanish, English, French, and Haitian Creole.

6. Orange County, California (3.15 million people)

Orange County, California is home to the cities of Anaheim, Santa Ana, Newport Beach, and Laguna Beach. Popular tourist attractions in the county include Disneyland and Knott’s Berry Farm. Cultural sites in the area include the Richard Nixon Presidential Library, the Ronald Reagan Federal Building, and the Crystal Cathedral. Among Orange County's many historical landmarks include the Balboa Inn, the Carnegie Library, and Fullerton’s Masonic Temple. Due to its location bordering the Pacific Ocean, the county is known for its scenic beaches and surfing culture. Local sports lovers also have the opportunity to follow the National Hockey League’s Anaheim Ducks, as well as Major League Baseball’s Los Angeles Angels of Anaheim team.

5. San Diego County, California (3.26 million people)

San Diego County, California includes 70 miles of California coastline, and is the home of 16 naval and military facilities. As such, it serves as a major center for U.S. military operations. The county also includes the San Diego National Wildlife Refuge Complex, which was founded in 1972. This series of refuges was established in order to protect the flora and fauna native to the local area. Tourism plays a major role in the county’s economy, and popular sites for visitors here include Sea World, Lego Land, an array of shopping malls, and such museums as the San Diego Museum of Art, the San Diego Air and Space Museum, and the USS Midway Museum. The county also features athletic facilities like the Torrey Pines Golf Course, as well as being home to the National Football League's San Diego Chargers and Major League Baseball’s San Diego Padres.

4. Maricopa County, Arizona (4.09 million people)

Maricopa County can be found in the south-central region of Arizona. Established in 1871, the county contains the state capital of Phoenix, as well as Tempe, Mesa, and Glendale. The fact that the county was named after the Maricopa Indian tribe reflects the rich Native American history of the area, which is continued as the county remains a home for five Native American Reservations. Historic sites in the county include a variety of protected archaeological areas, the B. B. Moeur Activity Building (located in Tempe and currently the home of the Mars Space Flight Facility), and Mesa Grande, a cultural park which highlights the classical Hohokam Native American styles. Several major universities are also located in Maricopa County, including Arizona State University and the University of Phoenix.

3. Harris County, Texas (4.44 million people)

Founded in 1836, Harris County, Texas includes the city of Houston. It’s home to several major universities, including the University of Houston, Texas Southern University, Strayer University, North American University, Houston Graduate School of Theology, the College of Biblical Studies, Houston Baptist University, the University of St. Thomas, and Rice University. The county is also the location of the Ellington Field Joint Reserve Base used by the U.S. military and National Aeronautics and Space Administration (NASA), as well as the George Bush International Airport. Among the many historic places in Harris County are the Houston Waterworks built in 1879, the Houston Cotton Exchange Building built in 1884, the Apollo Mission Control Center, and the Astrodome (former home of major league Baseball's Houston Astros), which was once referred to as being the "Eighth Wonder of the World". The Congregation Beth Israel of Houston, which opened in 1854, is also located in Harris County, and holds the distinction of being the oldest Jewish congregation in the entire state of Texas.

2. Cook County, Illinois (5.25 million people)

Almost half of all the citizens living in Illinois call Cook County their home. Founded in 1831, the county is located in the northeastern portion of the state. It encompasses a number of cities, including Evanston and Arlington Heights, as well as, of course, the major urban center of Chicago, which is itself home to a population of just under three million people. Cook County is composed of 30 townships, a large number of villages, and the town of Cicero. The county is made up of various natural environments, including wetlands, forests, lakes, and prairies. The Forest Preserve District of Cook County is responsible for managing a network of lands which have been set aside for protection and the purpose of conservation.

1. Los Angeles County, California (10.12 million people)

As the most populous county in the United States, Los Angeles County is home to approximately a quarter of California’s total population. Established in 1850, the county occupies an area of some 4,751 square miles, including the cities of Los Angeles, Pasadena, and Hollywood. The county is home to a wide array of educational facilities including the University of California, Los Angeles (or UCLA), Pepperdine University, American Jewish University, Azusa Pacific University, Biola, the California Institute of Technology, the University of Southern California, Loyola Marymount, and The Art Institute of California (located in Santa Monica). Among the cultural attractions to be found in the county are the Museum of Contemporary Art, the J. Paul Getty Center, and the Museum of Tolerance, which focuses on racism and the Holocaust. Because of its strong historical ties to the entertainment industry, many TV shows and movies are still filmed in Los Angeles County.

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