The surviving mission buildings are the state's oldest structures, and its most-visited historic monuments.
In the end, the missions had mixed results in their objectives: to convert, educate, and transform the natives into Spanish colonial citizens.
The Alta California government secularized the missions after the passage of the Mexican secularization act of 1833.
This divided the mission lands into land grants, which became many of the Ranchos of California.
The missions were to be interconnected by an overland route which later became known as the Camino Real. (who, in 1767, along with his fellow priests, had taken control over a group of missions in Baja California Peninsula previously administered by the Jesuits). Fermín Francisco de Lasuén took up Serra's work and established nine more mission sites, from 1786 through 1798; others established the last three compounds, along with at least five asistencias (mission assistance outposts). Pedro Estévan Tápis proposed establishing a mission on one of the Channel Islands in the Pacific Ocean off San Pedro Harbor in 1784, with either Santa Catalina or Santa Cruz (known as Limú to the Tongva residents) being the most likely locations, the reasoning being that an offshore mission might have attracted potential people to convert who were not living on the mainland, and could have been an effective measure to restrict smuggling operations.
The detailed planning and direction of the missions was to be carried out by Friar Junípero Serra, O. Governor José Joaquín de Arrillaga approved the plan the following year, however an outbreak of sarampion (measles) killing some 200 Tongva people coupled with a scarcity of land for agriculture and potable water left the success of such a venture in doubt, so no effort to found an island mission was ever made. Mariano Payeras, "Comisario Prefecto" of the California missions, visited Cañada de Santa Ysabel east of Mission San Diego de Alcalá as part of a plan to establish an entire chain of inland missions.