In San Juan Bautista, the José Castro House witnessed nearly a decade of cultural and political change between its construction in 1839 and the annexation of California by the United States in 1848. This was a time of demographic and political transition in California, as Mexicans, Americans, and both Latino and Anglo Californians fought for control of the Mexican province. Ownership of the José Castro House, a National Historic Landmark, passed from the Californio Castro family to the Irish American Breen family in 1848. Today, the José Castro House is part of the San Juan Bautista Plaza Historic District where the San Juan Bautista State Historical Park offers visitors a chance to explore life during the eras of Spanish, Mexican, and early American California.

General José Antonio Castro was a politician and military leader during the 1830s and 1840s in Alta California, then a Mexican province. As a young man, Castro was a vocal and active supporter of Californian self-rule and semi-independence from Mexico. At various times over the course of his life, Castro served as governor and general of both Alta and Baja California. His father, José Tibúrcio Castro, was the administrator of the secularized San Juan Bautista Mission and, under his authority, the California government distributed mission land to Castro relatives and friends. The elder Castro gave his son land on the San Juan Bautista Plaza, and General Castro finished building his adobe house there in 1841. Castro used the house as a residence for his secretary and as an administrative base for his military operations. During the Bear Flag Revolt of 1846 and U.S.-Mexican War that followed, Castro was the commanding general of Alta California. This province included the present day American States of California, Arizona, Nevada, Utah, and parts of Wyoming and Colorado. After the United States annexed Alta California at the close of the war with Mexico, the Mexican government appointed Castro as governor of Baja California in the south.

The José Castro House is an example of Monterey-colonial architecture. Courtesy of the Historic American Buildings Survey

After the U.S.-Mexican War, José Castro gave his house in San Juan Bautista to an Irish American immigrant, Patrick Breen. Breen and his family were surviving members of the Donner Party. They arrived at San Juan Bautista in February 1848, nearly a year after completing their tragic journey through the Sierra Nevada. The Breens were the first English-speaking Americans to settle in the town, and Castro allowed them to live at his house until they could afford to buy it from him. One of Patrick Breen’s teenage sons made a fortune as a gold miner and the family used the money to purchase the adobe house from Castro in 1854. The Breen family established a working ranch and an inn at the plaza. Guests at the inn included gold rush prospectors and Ramona (1884) author Helen Hunt Jackson, who began writing her famous novel about Spanish California during her stay in San Juan Bautista in the early 1880s. The Breen family owned the house until 1935, when the State of California acquired the property and it became part of the San Juan Bautista State Historical Park.

The José Castro House, also known as the Castro-Breen Adobe, is a two-story Monterey-colonial style adobe, with a wood frame and second story porch. The Monterey style of architecture originated in California and blended Spanish colonial architecture with New England style. Massachusetts native Thomas Larkin built the first known Monterey house in 1835 in Monterey, California. The wood frame allows for more windows than regular adobe would have and can support a second floor. In the Monterey style, the porch and gable roof protect the adobe bricks and outer shell, made of mud, from water damage. The pane glass windows beside the front door of the José Castro House are not typical of Monterey architecture and reflect the influence of Greek Revival architecture, which was also popular during the 19th century. Today, the José Castro House property includes a half-acre orchard and garden.

San Juan Bautista State Historic Park uses the José Castro House as a fully furnished museum, where visitors are welcome to explore and see what the inside of the house looked like in the mid-19th century. Several other historic buildings in the plaza that are part of the San Juan Bautista Historic District are also open to the public. These buildings include the San Juan Bautista Mission, Plaza Hotel, and Zanetta House. The park offers guided tours of the plaza, a gift shop in the Plaza Hotel, costumed reenactments every first Saturday of the month, and activities for children. The San Juan Bautista Mission is a stop on the Juan Bautista de Anza National Historic Trail.