Established in 1721 along El Camino Real de los Tejas as part of Spain's effort to secure East Texas against French Louisiana, Mission Dolores was home day-to-day to one or two Franciscan priests and a small garrison of soldiers with their families, who together provided the mission's everyday religious and defensive functions. The local Ais Indians, for whom the mission was named, engaged with it only intermittently rather than living there permanently, and Spanish conversion efforts among them were largely unsuccessful. In practice the mission functioned less as a thriving religious community and more as a frontier trading post and diplomatic outpost, where Spanish missionaries and soldiers exchanged goods with area Native Americans and with French traders from nearby Natchitoches. It operated for roughly fifty years before Spain permanently abandoned it in 1773, once France's cession of Louisiana territory eliminated the strategic need for an East Texas buffer. The site's exact location was subsequently lost, with nineteenth- and early twentieth-century homes built atop it, until archaeological work beginning in the 1960s confirmed its location. The City of San Augustine acquired and began preserving the site in the early 1990s, opening a small museum, and the Texas Historical Commission took ownership in 2016, developing it into today's Mission Dolores State Historic Site. Its everyday function now is entirely interpretive: a visitor center and museum, walking trails over the archaeological remains, and ongoing excavation and public-education programming preserve and explain the site's Spanish colonial and Ais history for visitors.