The Espada community of San Antonio has the unique distinction of participating in the oldest continually operating irrigation system in the United States. In 1731 Father Pedro Muñoz of the College of Santa Cruz de Querétaro made a contract with the Pacaos Indians stating that they would be the owners of San Francisco de la Espada Mission, one of the early Spanish missions on the San Antonio River. The aqueduct, friary, and sacristy were completed in 1745. It was at least nine years before any other permanent structure was built. A small chapel was completed in 1756, but the roof caved in, and it had to be torn down by 1777. The stone Indian quarters and the granary were the most permanent structures in the compound. The lower section between the arches of the aqueduct became detached from the foundation but stood, because they were covered with a crust of lime that solidified. A similar process apparently occurred to help cement the Espada dam as well. The mission compound met the San Antonio River at its northern end. A fence needed only to be built along the west side of the southern fields, as the compound and Minita Creek provided boundaries at the northern and southern end, and the San Antonio River formed the eastern boundary. A conflict between the Indians and local settlers in 1736 and a smallpox and measles epidemic greatly reduced the number of occupants in Espada mission. Ironically, the priests at the missions may have contributed to the spread of disease as they visited every village, going from one to another almost on a daily schedule, in an attempt to administer last rites. Father Muñoz was replaced by Father Ignacio Ysasmendi in 1736. Father Ysasmendi died in 1739 during the smallpox and measles epidemic. In 1745 Father Francisco Xavier Ortiz came from Querétaro, Mexico, to inspect all the Queretaran missions north of the Río Bravo (Rio Grande). In his report the mission Espada was reported to have irrigated fields in which vegetables and cotton grew. That year eight bushels of corn were planted, yielding 1,600 bushels, and the harvest included cotton, melon, and pumpkins. Eighty-one horses were used by the Indian cowboys, and each year surplus foods were sold at the presidio for supplies.
In 1772 the four Queretaran missions, including San Francisco de la Espada, were transferred to the missionaries from the College of Zacatecas. At this time inventories were taken of Espada as well as the other three Queretaran missions. The mission had two fenced fields. The fences were built from strong mesquite limbs, which were nailed and tied together. The larger field was planted with corn and beans, and the smaller field contained cotton and corn. In addition there was a fenced orchard with peach trees and vegetables. The acequia watered the three fields. It was reinforced with slabs of caliche where it crossed depressions. To cross La Piedra Creek an aqueduct of thirty-eight varas (roughly 100 feet) in length had been constructed with two culverts to allow the creek to flow. The irrigation dam was made of stone, forty-seven varas long, two varas wide, and three varas high. The Espada mission buildings were incomplete due to a lack of stone. After 1772 increased Indian depredations, recurrent disease, and hunger led to the secularization of Espada on June 25, 1794. On July 11, 1794, Governor Manuel Muñoz came to Mission Espada and in the presence of Father Pedro Norena officially divided the lands among the fifteen mostly old and lame Indians. Muñoz encouraged the Indians to rent the remaining lands that could be farmed to Spaniards or Indian converts. Some of this land was irrigated and some not. He also stressed that the squatters on mission lands should pay rent. A special piece of land for a garden was held for the priest of Espada. At this time the mission had 1,150 head of small livestock, including 188 goats, seven pigs, three horses, three mules, one cow, and one heifer, a pair of stocks for holding prisoners, and a compass.
In 1804 Espada had an Indian population of thirty-seven (twenty-one males, sixteen females) and a Spanish population of fifty-seven (thirty-three males and twenty-four females). By April 1820 the Spanish alcalde of Espada, Manuel Díaz, wrote that services of a teacher were obtained for the community. On February 29, 1824, Father José Antonio Díaz de León surrendered the church, and in September 1831 the governor of Coahuila and Texas, José María Letona, sent orders stating that all mission property be sold at auction. A protest by the citizens of the Espada mission against the sale of mission land to José Antonio de la Garza occurred in February 1834. An official copy of the land divisions from 1834 filed on July 9, 1874, included several of the Indian names listed in the 1794 land division as land holders. Also in the 1834 division are the Bustillos and the Garzas. The turbulent years after 1834 leave little record of the activities at Espada. It was recorded that James Bowie and James W. Fannin made a stand at Espada on October 22, 1835. Several travelers visited the mission in the 1840s, among them George Wilkins Kendall. In 1887 a proposal was made and plans were drawn up to construct an acequia from the end of the Espada acequia, southward along the river past the confluence of the Medina River. From 1858 to 1907 the Reverend Francis Bouchu served as pastor of Espada. During his extended stay he undertook to restore many of the collapsed buildings inside the compound. After Father Bouchu left, the church was temporarily closed for repairs and reopened in 1915. At this time the diocesan priests followed the Claretian Fathers, and a school was opened inside the compound of Espada by the Sisters of the Incarnate Word and Blessed Sacrament. The community was joined by the Redemptionists from 1923 to 1956. In 1967 the school was discontinued, and the Franciscans returned on the invitation of the archbishop. From 1967 through 1986 the community continued to maintain the irrigation system through the efforts of the Espada Ditch Company.