City (pop., 2000: 629,208), capital of San Luis Potosí state, Mexico.
Situated on the central plateau, it is about 6,100 ft (1,850 m) above sea level. Founded as a Franciscan mission in 1583 and made a city in 1658, it was the centre of the region's colonial administration. It was the site of Benito Juárez 's government in 1863. In 1910 Francisco Madero drew up the basic social and political program of the Mexican Revolution in the city. It is the hub of a rich silver mining and agricultural region and is a leading manufacturing, metal smelting, and refining centre.