The Main and Military Plazas Historic District incorporates two plazas and surrounding blocks that are inextricably linked with the history of San Antonio. The area has been the heart of the city since the 18th century and today is the commercial and government center of San Antonio. Established in 1722, Military Plaza functioned as a parade ground and market for Spanish soldiers. In 1836, it was the site of the bloodiest battle in Texas' struggle for independence from Mexico. The area of Main Plaza was the site of the first authorized city in Texas (c.1731) and was settled by families from the Canary Islands whose one-story homes encircled the plaza. Both plazas were ringed by small residences, replaced during the post-Civil War boom by masonry commercial and government structures. The architecture of the buildings surrounding the plazas exemplifies San Antonio's growth and diversity over a period spanning more than 200 years. Among the best examples are the Spanish Governor's Palace (c.1749); the Melchoir de la Garza House (c.1800), a one-story caliche block cottage and the only remaining example of the type of homes that once ringed the plazas; the San Fernando Cathedral (c .1740; c.1870); San Antonio's City Hall (c.1880) an elaborate three-story Italian Renaissance Revival structure; and the Rand Building (c.1920) an eight-story building showing Chicago Style influences.