Claim: Texas is comprised of rolling plains and rugged hills.

Texas -LRB- -LSB- ˈtɛksəs -RSB- , -LSB- localˈtɛksᵻz -RSB- Texas or Tejas -LSB- ˈtexas -RSB- -RRB- 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 Texan state flag and on the Texan state seal . The origin of Texas 's name is from the word `` Tejas , '' which means `` friends '' in the Caddo language .   Due to its size and geologic features such as the Balcones Fault , Texas contains diverse landscapes that resemble both the U.S. Southern and Southwestern regions . Although Texas is popularly associated with the U.S. southwestern deserts , less than 10 % of Texas ' land area is desert . Most of the population centers are located 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 `` For example , as used by the large Grand Prairie -- based national and international amusement park operator Six Flags 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 .   One Texan industry that thrived after the Civil War was cattle . Due to its long history as a center of the industry , Texas is associated with the image of the cowboy . The state 's economic fortunes changed in the early 20th century , when oil discoveries initiated an economic boom in the state . 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 nation in export revenue since 2002 and has the second-highest gross state product .