Texas is the second most populous and the second most extensive of the 50 states in the United States of America, and the most extensive state of the 48 contiguous United States. Located in the South Central United States, Texas shares an international border with the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south, and borders the US states of New Mexico to the west, Oklahoma to the north, Arkansas to the northeast, and Louisiana to the east.

Houston is the largest city in Texas and the fourth-largest in the United States, while San Antonio is the second largest in the state and seventh largest in the United States. Dallas–Fort Worth and Greater Houston are the fourth and fifth largest United States metropolitan areas, respectively. Other major cities include El Paso and Austin—the state capital. Texas is nicknamed the Lone Star State to signify Texas as a former 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 Texas state seal today.

The term "six flags over Texas" came from the several nations that had ruled over the territory. Spain was the first European country to claim the area of Texas. France held a short-lived colony in Texas. Mexico controlled the territory until 1836 when Texas won its independence, becoming an independent Republic. In 1845 it joined the United States as the 28th state. The state's annexation set off a chain of events that caused the Mexican–American War in 1846. A slave state, Texas declared its secession from the United States in early 1861, joining the Confederate States of America during the American Civil War. After the war and its restoration to the Union, Texas entered a long period of economic stagnation.

The name Texas, based on the Caddo word tejas meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in East Texas.

During the Spanish colonial rule, the area was officially known as the Nuevo Reino de Filipinas: La Provincia de Texas. Antonio Margil de Jesús was known to be the first person to use the name in a letter to the Viceroy of Mexico in July 20, 1716. The name was not popularly used in daily speech but often appeared in legal documents until the end of the 1800s.