Mission Santa Barbara-often called the "Queen of the Missions" because of its profound beauty-was begun in 1786 and dedicated in 1820, eight years after a large earthquake shook the original mission structure to the ground. It was rebuilt, this time under the influence of an ancient Roman architectural compiler named Vitruvius. His work informs many of the attempts at mission restoration that swept California in the 1820s and 1830s. Mission Santa Barbara looks today essentially as it did at the 1820 dedication.

The founding of the presidio began a long period of Spanish-Mxican rule in which military and church were tightly intertwined. Spanish land grants led to the creation of large ranchos within the Santa Barbara district, and it became one of the wealthiest of the districts under the governor at Monterey. This colonial period of Santa Barbara's history lent the city its distinct and beautiful architectural style-white stucco buildings and red-tile roofs.

In 1821, Mexico declared its independence from Spain,and Alta California became a territory of Mexico The presidio continued to govern the city and remained an important aspect of Santa Barbara life and culture until 1846, when General John C. Femont and his American battalion came over the San Marcos Pass in the mountains north of the city and raised the U.S. flag at Santa Barbara. In 1848, California officially became a U.S. territory.

On April 9, 1850, Santa Barbara became a legal city. Later that year, California became the 31st state in the Union. With the secularization of the missions in 1834 came the gradual loss of the mission system at Santa Barbara. The holdings and land were leased, the Chumash inhabitants of mission housing ultimately left, and the church was turned over to the Franciscans, who remain at the mission today.