Spain claimed ownership of the territory of Texas in 1519, which comprised part of the present-day U.S. state of Texas, including the land north of the Medina and Nueces Rivers, but did not attempt to colonize the area until after locating evidence of the failed French colony of Fort Saint Louis in 1689. In 1690 Alonso de León escorted several Catholic missionaries to east Texas, where they established the first mission in Texas. When native tribes resisted the Spanish invasion of their homeland, the missionaries returned to Mexico, abandoning Texas for the next two decades. The Spanish returned to southeastern Texas in 1716, establishing several missions and a presidio to maintain a buffer between Spanish territory and the French colonial Louisiana district of New France. Two years later in 1718, the first civilian settlement in Texas, San Antonio, originated as a way station between the missions and the next-nearest existing settlement. The new town soon became a target for raids by the Lipan Apache.

The raids continued periodically for almost three decades, until Spanish settlers and the Lipan Apache peoples made peace in 1749. But the treaty angered the enemies of the Apache, and resulted in raids on Spanish settlements by the Comanche, Tonkawa, and Hasinai tribes. Fear of Indian attacks and the remoteness of the area from the rest of the Viceroyalty discouraged European settlers from moving to Texas. It remained one of the provinces least-populated by immigrants. The threat of attacks did not decrease until 1785, when Spain and the Comanche peoples made a peace agreement. The Comanche tribe later assisted in defeating the Lipan Apache and Karankawa tribes, who had continued to cause difficulties for settlers. An increase in the number of missions in the province allowed for peaceful Christian conversions of other tribes.

France formally relinquished its claim to its region of Texas in 1762, when it ceded French Louisiana to the Spanish Empire. The inclusion of Spanish Louisiana into New Spain meant that Tejas lost its significance as essentially a buffer province. The easternmost Texas settlements were disbanded, with the population relocating to San Antonio. However, in 1799 Spain gave Louisiana back to France, and in 1803 Napoléon Bonaparte (First Consul of the French Republic) sold the territory to the United States as part of the Louisiana Purchase, U.S. President Thomas Jefferson (in office: 1801 to 1809) insisted that the purchase included all land to the east of the Rocky Mountains and to the north of the Rio Grande, although its large southwestern expanse lay within New Spain. The territorial ambiguity remained unresolved until the Adams–Onís Treaty compromise in 1819, when Spain ceded Spanish Florida to the United States in return for recognition of the Sabine River as the eastern boundary of Spanish Texas and western boundary of the Missouri Territory. The United States relinquished their claims on the vast Spanish territories west of the Sabine River and extending into Santa Fe de Nuevo México province (New Mexico).

During the Mexican War of Independence of 1810 to 1821 Texas experienced much turmoil. Three years later the Republican Army of the North, consisting primarily of Indians and of citizens of the United States, overthrew the Spanish government in Tejas and executed Salcedo. The Spanish responded brutally, and by 1820 fewer than 2000 Hispanic citizens remained in Texas. The Mexican independence movement forced Spain to relinquish its control of New Spain in 1821, with Texas becoming in 1824 part of the state of Coahuila y Tejas within the newly formed Mexico in the period in Texas history known as Mexican Texas (1821-1836).

The Spanish left a deep mark on Texas. Their European livestock caused mesquite to spread inland, while farmers tilled and irrigated the land, changing the landscape forever. The Spanish provided the names for many of the rivers, towns, and counties that currently exist, and Spanish architectural concepts still flourish. Although Texas eventually adopted much of the Anglo-American legal system, many Spanish legal practices survived, including the concepts of a homestead exemption and of community property.