Texas was originally part of Mexico, achieving independence as the Republic of Texas in 1836. The United States acquired the area of Texas through annexation and Texas was admitted to the Union on March 1, 1845, as the 28th state. At the time of statehood, Texas included part of present-day Colorado, Kansas, New Mexico, Oklahoma, and Wyoming. Texas sold territory to the United States in 1850 to assume generally the same boundary as the present state, but there were some subsequent revisions. In 1896, the Supreme Court ruled the Texas claim to the Greer County area in southwest Oklahoma to be invalid, and the area was officially deemed to be part of Oklahoma. An additional boundary dispute with Oklahoma was settled in 1930 by adding a narrow strip of territory to Texas. As the Rio Grande has changed its course, the United States and the Republic of Mexico have made periodic adjustments to their boundary that affected the boundary of Texas. Census data for Texas are available beginning with the 1850 census.

Texas is a large state in the southern U.S. with deserts, pine forests and the Rio Grande, a river that forms its border with Mexico. In its biggest city, Houston, the Museum of Fine Arts houses works by well-known Impressionist and Renaissance painters, while Space Center Houston offers interactive displays engineered by NASA. Austin, the capital, is known for its eclectic music scene.

The first European base was established in 1680 in El Paso, Texas with the exiled Spaniards and Native Americans from the Isleta Pueblo during the Pueblo Revolt, also known as Popé's Rebellion, from northern New Mexico. In 1682, René-Robert Cavelier, Sieur de La Salle established a French colony, Fort Saint Louis, near Matagorda Bay. The colony was killed off by Native Americans after three years, but Spanish authorities felt pressed to establish settlements to keep their claim to the land. Several missions were established in East Texas; they were abandoned in 1691. .

Texas became an independent nation, the Republic of Texas. Attracted by the rich lands for cotton plantations and ranching, tens of thousands of immigrants arrived from the U.S. and from Germany as well. In 1845, Texas joined the United States, becoming the 28th state. Texas declared its secession from the United States in 1861 to join the Confederate States of America. Only a few battles of the American Civil War were fought in Texas; most Texas regiments served in the east. When the war ended, the enslaved African Americans were freed.

ACotton, ranching, and farming dominated the economy, with railroad construction after 1870 a major factor in the development of new cities away from rivers and waterways. Toward the end of the 19th century, timber became an important industry in Texas as well. In 1901 a petroleum discovery at Spindletop Hill, near Beaumont, was developed as the most productive oil well the world had ever seen. The wave of oil speculation and discovery that followed came to be known as the "Oil Boom", permanently transforming and enriching the economy of Texas. Agriculture and ranching gave way to a service-oriented society after the boom years of World War II..

Politically, Texas changed from the virtually one-party Democratic state achieved following disenfranchisement, to a highly contested political scene, until 2000 when it was solidly Republican. The economy of Texas has continued to grow rapidly, becoming the second-largest state in population in 1994, and became economically highly diversified, with a growing base in high technology.