Texas is the second largest state in the United States by both area and population. Geographically located in the South Central region of the country, Texas shares borders with the U.S. states of Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the southwest, while the Gulf of Mexico is to the southeast.

Houston is the most populous city in Texas and the fourth largest in the U.S., while San Antonio is the second-most populous in the state and seventh largest in the U.S. Dallas–Fort Worth and Greater Houston are the fourth and fifth largest metropolitan statistical areas in the country, respectively. Other major cities include Austin, the second-most populous state capital in the U.S., and El Paso. Texas is nicknamed “The Lone Star State” to signify its former status as an independent republic, and as a reminder of the state’s struggle for independence from Mexico. The “Lone Star” can be found on the Texas state flag and on the Texan state seal. The origin of Texas’s name is from the word taysha, which means “friends” in the Caddo language.

Due to its size and geologic features such as the Balcones Fault, Texas contains diverse landscapes common to both the U.S. Southern and Southwestern regions. Although Texas is popularly associated with the U.S. southwestern deserts, less than 10% of Texas’s land area is desert. Most of the population centers are in areas of former prairies, grasslands, forests, and the coastline. Traveling from east to west, one can observe terrain that ranges from coastal swamps and piney woods, to rolling plains and rugged hills, and finally the desert and mountains of the Big Bend.

The term “six flags over Texas refers to several nations that have ruled over the territory. Spain was the first European country to claim the area of Texas. France held a short-lived colony. Mexico controlled the territory until 1836 when Texas won its independence, becoming an independent Republic. In 1845, Texas joined the union as the 28th state. The state’s annexation set off a chain of events that led to the Mexican–American War in 1846. A slave state before the American Civil War, Texas declared its secession from the U.S. in early 1861, and officially joined the Confederate States of America on March 2 of the same year. After the Civil War and the restoration of its representation in the federal government, Texas entered a long period of economic stagnation.

Historically four major industries shaped the Texas economy prior to World War II: cattle and bison, cotton, timber, and oil. Before and after the U.S. Civil War the cattle industry, which Texas came to dominate, was a major economic driver for the state, thus creating 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. It was ultimately, though, the discovery of major petroleum deposits (Spindletop in particular) that initiated an economic boom which became the driving force behind the economy for much of the 20th century. With strong investments in universities, Texas developed a diversified economy and high tech industry in the mid-20th century. As of 2015, it is second on the list of the most Fortune 500 companies with 54. With a growing base of industry, the state leads in many industries, including 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. If Texas were a sovereign state, it would be the 10th largest economy in the world

The name Texas, based on the Caddo word táysha “friend”, was applied, in the spelling Tejas or Texas, by the Spanish to the Caddo themselves, specifically the Hasinai Confederacy, the final -s representing the Spanish plural.The Mission San Francisco de los Tejas was completed near the Hasinai village of Nabedaches in May 1690, in what is now Houston County, East Texas.

During Spanish colonial rule, in the 18th century, the area was known as Nuevo Reino de Filipinas “New Kingdom of the Philippines”, or as provincia de los Tejas “province of the Tejas”, later also provincia de Texas (or de Tejas), “province of Texas”. It was incorporated as provincia de Texas into the Mexican Empire in 1821, and declared a republic in 1836. The Royal Spanish Academy recognizes both spellings, Tejas and Texas, as Spanish-language forms of the name of the US State of Texas.The English pronunciation with /ks/ is unetymological, and based in the value of the letter x in historical Spanish orthography. Alternative etymologies of the name advanced in the late 19th century connected the Spanish teja “rooftile”, the plural tejas being used to designate indigenous Pueblo settlements. A 1760s map by Jacques-Nicolas Bellin shows a village named Teijas on Trinity River, close to the site of modern Crockett.

Geography

Texas is the second-largest U.S. state, after Alaska, with an area of 268,820 square miles (696,200 km2). Though 10% larger than France and almost twice as large as Germany or Japan, it ranks only 27th worldwide amongst country subdivisions by size. If it were an independent country, Texas would be the 40th largest behind Chile and Zambia.

Texas is in the south central part of the United States of America. Three of its borders are defined by rivers. The Rio Grande forms a natural border with the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south. The Red River forms a natural border with Oklahoma and Arkansas to the north. The Sabine River forms a natural border with Louisiana to the east. The Texas Panhandle has an eastern border with Oklahoma at 100° W, a northern border with Oklahoma at 36°30′ N and a western border with New Mexico at 103° W. El Paso lies on the state’s western tip at 32° N and the Rio Grande.

With 10 climatic regions, 14 soil regions and 11 distinct ecological regions, regional classification becomes problematic with differences in soils, topography, geology, rainfall, and plant and animal communities. One classification system divides Texas, in order from southeast to west, into the following: Gulf Coastal Plains, Interior Lowlands, Great Plains, and Basin and Range Province.

The Gulf Coastal Plains region wraps around the Gulf of Mexico on the southeast section of the state. Vegetation in this region consists of thick piney woods. The Interior Lowlands region consists of gently rolling to hilly forested land and is part of a larger pine-hardwood forest.

The Great Plains region in central Texas is in spans through the state’s panhandle and Llano Estacado to the state’s hill country near Austin. This region is dominated by prairie and steppe. “Far West Texas” or the “Trans-Pecos” region is the state’s Basin and Range Province. The most varied of the regions, this area includes Sand Hills, the Stockton Plateau, desert valleys, wooded mountain slopes and desert grasslands.

Texas has 3,700 named streams and 15 major rivers, with the Rio Grande as the largest. Other major rivers include the Pecos, the Brazos, Colorado, and Red River. While Texas has few natural lakes, Texans have built over 100 artificial reservoirs.

The size and unique history of Texas make its regional affiliation debatable; it can be fairly considered a Southern or a Southwestern state, or both. The vast geographic, economic, and cultural diversity within the state itself prohibits easy categorization of the whole state into a recognized region of the United States. Notable extremes range from East Texas which is often considered an extension of the Deep South, to Far West Texas which is generally acknowledged to be part of the interior Southwest.

Geology

Texas is the southernmost part of the Great Plains, which ends in the south against the folded Sierra Madre Occidental of Mexico. The continental crust forms a stable Mesoproterozoic craton which changes across a broad continental margin and transitional crust into true oceanic crust of the Gulf of Mexico. The oldest rocks in Texas date from the Mesoproterozoic and are about 1,600 million years old.

These Precambrian igneous and metamorphic rocks underlie most of the state, and are exposed in three places: Llano uplift, Van Horn, and the Franklin