San Juan Bautista Mission was founded on St. John's Day, June 24, 1699, on the Río de Sabinas, some twenty-five miles north of Lampazos, Nuevo León, Mexico, with 150 Indians of various Coahuiltecan bands. It lasted only a few months at this site, then was reestablished on January 1, 1700, at the site of present-day Guerrero, Coahuila, thirty-five miles down the Rio Grande from Eagle Pass and Piedras Negras. The founding Franciscans—fathers Francisco Hidalgo, Antonio de San Buenaventura y Olivares, and Marcos de Guereña of the College of Santa Cruz de Querétaro—were assisted by a squad of soldiers under Capt. Diego Ramón. The new site, five miles from the Rio Grande, was strategically located near a series of crossings providing access to Texas. Here San Juan Bautista, growing into a complex of three missions, a presidio, and a civilian settlement, served as a way station and gateway for expeditions to the Texas interior from 1700 until the Mexican War.
On March 1, 1700, Mission San Juan Bautista was joined by a second mission, San Francisco Solano. A year later the viceroy, responding to pleas of the missionaries for protection, provided a roving company under Ramón's command. In 1703 a military plaza was laid out, and the "flying company" became the garrison of Presidio de San Juan Bautista del Río Grande. The third mission, San Bernardo, was founded in the spring of 1702. The three missions stood in a tight triangle on either side of the spring-fed arroyo that supplied their water. San Juan was situated adjacent to the presidio until it was moved a short distance west of the village about 1740. Tillable land and water were not sufficient for the four entities. San Francisco Solano was moved in 1703 to a site sixteen leagues west, near the site of present Zaragosa, Coahuila. In 1708 it was returned to the Rio Grande at Villa de San José, "five leagues" north of San Juan Bautista.
From 1700 to 1716 the San Juan Bautista settlement was the most advanced on New Spain's northeastern frontier. As such it served as a base for exploration beyond the Rio Grande: in 1700, Father Olivares's trek to the Frio River seeking mission neophytes; Ramón's Indian campaign along the Nueces River in 1707; and the Espinosa-Olivares-Aguirre expedition to the Colorado in 1709. San Juan Bautista served also as a listening post for news of the French, who in 1699 had settled at Biloxi Bay and were exploring west of the Mississippi. The French cavalier Louis Juchereau de St. Denis arrived at San Juan Bautista from Mobile in the summer of 1714 to entice the Spaniards to illicit trade and marry the commandant's granddaughter.
In every respect San Juan Bautista was the mother of the Texas missions. In 1716 it launched an entrada in the charge of Domingo Ramón—who later commanded the first Texas presidio—to reestablish the East Texas missions abandoned in 1693, and followed up with supply expeditions. Governor Martín de Alarcón launched his founding expedition to San Antonio from San Juan in 1718, after spending the winter there. At that time Father Olivares moved San Francisco Solano to the San Antonio site, where it became Mission San Antonio de Valero, later known as the Alamo. San Juan provided grain, cattle, and remounts to bolster the faltering expedition of the Marqués de San Miguel de Aguayo in 1721–22. Nuestra Señora de Loreto Presidio, founded by Aguayo, was commanded in succession by two members of the Ramón family from San Juan Bautista, Domingo and his son Diego III. At midcentury San Juan provided livestock and provisions to the San Xavier missions and the Apache mission on the San Saba River. After the latter was destroyed by the northern tribes in March 1758, the San Juan Bautista commandant, Manuel Rodríguez, took a company of soldiers to join the punitive expedition and remained a year in temporary command of the San Sabá garrison. The renewed missionary effort for the Apaches on the upper Nueces River was a joint enterprise of the new commandant at San Sabá and the Rio Grande missions.
Soldiers of Presidio de San Juan Bautista provided escorts for travelers and supply trains to Texas, joined Indian campaigns, and played a vital role in exploration. In 1731 they escorted the Canary Islanders on the last leg of their journey to San Antonio. They assisted explorations up the Rio Grande by José de Barroterán in 1729 and Blas María de la Garza Falcón in 1735. In 1747 they reconnoitered the Rio Grande from their post to its mouth in conjunction with José de Escandón and assisted Pedro de Rábago y Terán in opening a trail from Coahuila to La Junta de Los Ríos. In 1732 and 1739 troops under Manuel Rodríguez joined Apache campaigns led by Texas governor Juan Antonio Bustillo y Ceballos and José de Urrutia. Rodríguez, at age seventy-one, led an expedition up the Rio Grande to the presidio of El Paso in 1769, engaging hostile Indians along the way.
The New Regulations for Presidios of 1772 brought great change to San Juan Bautista. With establishment of the Provincias Internas and formation of a defense line extending west to the Gulf of California, San Juan Bautista troops were involved almost continuously in Apache campaigns, both in the Bolsón de Mabimí and north of the Rio Grande. In 1775 San Juan Bautista's force was one of several to take part in the coordinated campaign extending across southwestern Texas into New Mexico and Arizona. Vicente Rodríguez, who had succeeded his brother Manuel as commandant of the presidio, at age seventy-six led the Rio Grande troops north to the abandoned Presidio de San Sabá, then up the Pecos River into New Mexico.
On November 22, 1772, missions San Juan and San Bernardo were transferred from the College of Santa Cruz de Querétaro to the province of Jalisco. In 1781 they were again reassigned, this time to the Missionary College of Pachuca. The missions declined sharply. By 1790 Mission San Juan, which had baptized 1,434 Indians up to 1761, had only sixty-three natives under instruction. In 1797 citizens of the district petitioned for division of mission lands, but not until 1829, after Mexico had won independence from Spain, were the missions actually secularized and land distribution completed. Yet, for all practical purposes, the missions had ceased to function by 1810, when the Mexican War of Independence began. San Juan—the name changed to Puesto de Río Grande after its religious significance faded—was host to key figures of both sides during the insurgence, striking a delicate balance between factions. An 1827 legislative decree changed the name again, to Villa de Guerrero, honoring the Mexican patriot Vicente Guerrero. Even to this declining village, the processions of history still came. From January 10 to February 16, 1836, Guerrero served as the staging area for Antonio López de Santa Anna's army, marching on San Antonio de Béxar. In March 1842 Rafael Vásquez, having looted San Antonio, withdrew to Guerrero with his plunder. In June that year Gen. Adrián Woll assembled horses and men at Presidio del Río Grande and thence launched his invasion of Texas. The last invasion force came to Guerrero during the Mexican War, when on October 9, 1846, United States general John E. Wool encamped his Army of Chihuahua near the village.
After the war, traffic shifted more and more to Laredo and Eagle Pass, leaving Guerrero in the backwater, isolated even from Piedras Negras until the new Piedras Negras–Laredo highway was routed by the town in the 1970s. The town, centered by the plaza de armas of the former presidio, had significant architectural remains from the mission period at that time, but these were rapidly deteriorating. Ruins of the San Bernardo Mission church stood just north of the village. Mission San Juan Bautista, however, had been reduced to a pile of earth and stone, often disturbed by treasure hunters. A historical study published in 1968 awakened interest in Guerrero, and it became the focus of architectural, archeological, and ethnographical investigations funded by the Mexican government and the National Endowment for the Humanities. The San Juan Bautista site was partially excavated, and the San Bernardo ruins were stabilized. Guerrero's population in 1987 was estimated at 600.