Title: Spanish missions in Texas
Content:  Mission San Antonio de Valero was established on May 1, 1718, as the first Spanish mission along the San Antonio River. It was named for San Antonio de Padua, the patron saint of the mission's founder, Father Antonio de Olivares as well as for the viceroy of New Spain, the Marquis de Valero. The mission later became known as the Alamo. Its first location was west of San Pedro Springs, and after being moved several times, it was finally established above a bend in the San Antonio River, where it would be easy to defend. The early mission buildings were made of grass, and the first stone building was built in 1727. The building now known as the Alamo was not built until 1744, and most of its actual structure does not remain. The mission eventually 
Title: Alamo Mission in San Antonio
Content:  de Valero, named after Saint Anthony of Padua and the viceroy of New Spain, the Marquess of Valero. Alarcón, acting in his capacity as "General of the Provinces of the Kingdom of the New Philippines," formally entrusted the mission on May 1st to Father Antonio de San Buenaventura y Olivares in a foundation document, still preserved. The mission was located near a community of Coahuiltecans and was initially populated by three to five Indian converts from Mission San Francisco Solano near San Juan Bautista. One mile (two km) north of the mission, Alarcón built a fort, the Presidio San Antonio de Béxar. Close by, he founded the first civilian community 
Title: Spanish missions in Texas
Content:  Shortly after its founding, Mission San Antonio de Valero became overcrowded with refugees from the closed East Texas missions, and Father Antonio Margil received permission from the governor of Coahuila and Texas, the Marquis de San Miguel de Aguayo, to build a new mission. On February 23, 1720, the new mission, San José y San Miguel de Aguayo was established 5 mi south of San Antonio de Valero. Like San Antonio de Valero, Mission San José served the Coahuiltecan natives. The first buildings, made of brush, straw, and mud, were quickly replaced by large stone structures, including guest rooms, offices, a dining room, and a pantry. A heavy outer wall was built around the main part of the mission, and rooms for 350 Indians were built into the walls. A new church, which still stands, was constructed in 1768 from local limestone. The mission lands were given to its Indians in 1794, and mission activities officially ended in 1824. After that, the buildings were home to soldiers, the homeless, and bandits. It was restored in the 1930s and is now a state and national historic site.
Title: History of San Antonio
Content:  Fray Antonio de Olivares, who had established the Mission San Francisco Solano, went alone to a mission site that had been suggested by Father Damian Manzanet in 1690. He remained there alone after organizing the new mission, often meeting with the Indians of the area (Payaya Indians), gradually earning their love and respect. This mission was called San Antonio de Valero, a name derived from "San Antonio de Padua" and Viceroy New Spain, Marquess of Valero. It was located near a community of Coahuiltecan and was originally inhabited by indigenous three to five converted from Mission San Francisco Solano. Fray Antonio de Olivares also built the Presidio San Antonio de 
Title: Antonio de Olivares
Content:  the expedition which made first contact with the Pastia Indians and helped recruit them to help in the construction of the San Antonio missions. He remained at the site of the mission for some time, organizing everything with the Indians, and they constructed a straw structure with branches and mud near the head of the San Antonio River. This mission was called San Antonio de Valero, a name derived from "San Antonio de Padua" and Viceroy of New Spain, Marquess of Valero. The mission was located near a community of Coahuiltecan and was originally inhabited by about four indigenous tribes people converted from Mission San Francisco Solano. Unfortunately, his work 
Title: Mission San José (Texas)
Content:  Antonio de Valero. Like San Antonio de Valero, Mission San José served the Coahuiltecan Natives. The first buildings, made of brush, straw, and mud, were quickly replaced by large stone structures, including guest rooms, offices, a dining room, and a pantry. A heavy outer wall was built around the main part of the mission, and rooms for 350 Natives were built into the walls. A new church, which is still standing, was constructed in 1768 from local limestone. The mission lands were given to its Natives in 1794, and mission activities officially ended in 1824. After that, the buildings were home to soldiers, the homeless, and bandits. Starting in 1933, the Civil Works Administration and then the Works Progress 
Title: Alamo Mission in San Antonio
Content:  Texas, San Antonio de Béxar, which later developed into the present-day city of San Antonio, Texas. Within a year, the mission moved to the western bank of the river, where it was less likely to flood. Over the next several years, a chain of missions was established nearby. In 1724, after remnants of a Gulf Coast hurricane destroyed the existing structures at Misión San Antonio de Valero, the mission was moved to its current location. At the time, the new location was just across the San Antonio River from the town of San Antonio de Béxar and just north of a group of huts known as La Villita. Over the 
Title: Martín de Alarcón
Content:  On their arrival, the group first built a temporary structure to serve as a mission. The mission's founding document is dated May 1, 1718. Signed by Alarcón as "General of the Provinces of the Kingdom of the New Philippines," it creates a new mission of San Antonio de Valero, to replace the old mission of St Joseph due to lack of water at the former site, and the new foundation is in the name of the Viceroy of New Spain, the Marquess of Valero. The mission would much later become a garrison and gain fame as The Alamo. One mile (two km) north of the mission, Alarcón built a presidio, Presidio San Antonio de Bexar. Near the presidio, Alarcón chartered a new municipality, called Bejar (now known as San Antonio). Given a status higher than a village (pueblo) but lower than a city (ciudad), San Antonio became the only villa in Texas, and the colonists who settled there relied on farming and ranching to survive.
Title: Santa Ana Valley
Content:  This valley was named Vallejo de Santa Ana in 1769 after the Gaspar de Portolà expedition, of which Friar Junípero Serra was a part, as well as Sargeant José Antonio Yorba, and José Manuel Nieto. The mission located closest to the Santa Ana Valley is Mission San Juan Capistrano, which was built east of the San Joaquin Hills, in the present day city of San Juan Capistrano.
Title: San Antonio
Content:  clustered around the presidio and mission were the start of Villa de Béjar, destined to become the most important town in Spanish Texas. On May 1, the governor transferred ownership of the Mission San Antonio de Valero (later famous as The Alamo) to Fray Antonio de Olivares. On May 5, 1718, he commissioned the Presidio San Antonio de Béxar ("Béjar" in modern Spanish orthography) on the west side of the San Antonio River, one-fourth league from the mission. On February 14, 1719, the Marquis of San Miguel de Aguayo proposed to the king of Spain that 400 families be transported from the Canary Islands, Galicia, 

Question: when was the mission san antonio de valero built?
Answer: the 18th century.
1718.