Texas. Texas is the most populous state in the South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and an international border with the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south and southwest. Texas has a coastline on the Gulf of Mexico to the southeast. Covering 268,596 square miles, and with over 30 million residents as of 2023, it is the second-largest state by both area and population. Texas is nicknamed the Lone Star State for its former status as an independent republic. The Lone Star can be found on the Texas state flag and the Texas state seal. Spain was the first European country to claim and control the area of Texas. Following a short-lived colony controlled by France, Mexico controlled the territory until 1836 when Texas won its independence, becoming the Republic of Texas. In 1845, Texas joined the United States as the 28th state. The state's annexation set off a chain of events that led to the Mexican–American War in 1846. Following victory by the United States, Texas remained a slave state until the American Civil War, when it declared its secession from the Union in early 1861 before officially joining the Confederate States of America on March 2. After the Civil War and the restoration of its representation in the federal government, Texas entered a long period of economic stagnation. Historically, five major industries shaped the Texas economy prior to World War II: cattle, bison, cotton, timber, and oil. Before and after the Civil War, the cattle industry—which Texas came to dominate—was a major economic driver and created the traditional image of the Texas cowboy. In the later 19th century, cotton and lumber grew to be major industries as the cattle industry became less lucrative. Ultimately, the discovery of major petroleum deposits initiated an economic boom that became the driving force behind the economy for much of the 20th century. Texas developed a diversified economy and high tech industry during the mid-20th century. As of 2022, it has the most Fortune 500 company headquarters in the United States. With a growing base of industry, the state leads in many industries, including tourism, agriculture, petrochemicals, energy, computers and electronics, aerospace, and biomedical sciences. Texas has led the U.S. in state export revenue since 2002 and has the second-highest gross state product. The Dallas–Fort Worth metroplex and Greater Houston areas are the nation's fourth and fifth-most populous urban regions respectively. Its capital city is Austin. Due to its size and geologic features such as the Balcones Fault, Texas contains diverse landscapes common to both the U.S. Southern and the Southwestern regions. Most population centers are in areas of former prairies, grasslands, forests, and the coastline. Traveling from east to west, terrain ranges from coastal swamps and piney woods, to rolling plains and rugged hills, to the desert and mountains of the Big Bend. Texas lies between two major cultural spheres of Pre-Columbian North America: the Southwestern and the Plains areas. Archaeologists have found that three major Indigenous cultures lived in this territory, and reached their developmental peak before the first European contact. These were: the Ancestral Puebloans from the upper Rio Grande region, centered west of Texas; the Mississippian culture, also known as Mound Builders, which extended along the Mississippi River Valley east of Texas; and the civilizations of Mesoamerica, which were centered south of Texas. Influence of Teotihuacan in northern Mexico peaked around AD 500 and declined between the 8th and 10th centuries. When Europeans arrived in the Texas region, the language families present in the state were Caddoan, Atakapan, Athabaskan, Coahuiltecan, and Uto-Aztecan, in addition to several language isolates such as Tonkawa. Uto-Aztecan Puebloan and Jumano peoples lived neared the Rio Grande in the western portion of the state and the Athabaskan-speaking Apache tribes lived throughout the interior. The agricultural, mound-building Caddo controlled much of the northeastern part of the state, along the Red, Sabine, and Neches River basins. Atakapan peoples such as the Akokisa and Bidai lived along the northeastern Gulf Coast; the Karankawa lived along the central coast. At least one tribe of Coahuiltecans, the Aranama, lived in southern Texas. This entire culture group, primarily centered in northeastern Mexico, is now extinct. No culture was dominant across all of present-day Texas, and many peoples inhabited the area. Native American tribes who have lived inside the boundaries of present-day Texas include the Alabama, Apache, Atakapan, Bidai, Caddo, Aranama, Comanche, Choctaw, Coushatta, Hasinai, Jumano, Karankawa, Kickapoo, Kiowa, Tonkawa, and Wichita.