After 1834, the mission became an ordinary parish, and most of its huge land holdings were broken up into land grants called ranchos. The central community, however, remained in the same location and formed the nucleus of today's city of San Luis Obispo.
San Luis Obispo once had a burgeoning Chinatown in the vicinity of Palm St. and Chorro Street. Laborers were brought from China by Ah Louis in order to construct the Pacific Coast Railway, roads connecting San Luis Obispo to Paso Robles and Paso Robles to Cambria, and also the 1884 to 1894 tunneling through Cuesta Ridge for the Southern Pacific Railroad. The town's Chinatown revolved around Ah Louis Store and other Palm Street businesses owned and run by Chinese business people. Today, Mee Heng Low chop suey shop is all that remains of the culture, although a slightly Chinatown-themed commercial development has been planned. A display of some of the unearthed relics from this period can be seen on the first floor of the Palm Street parking garage, which was built over the location where Chinatown once stood. The San Luis Obispo Historical Society (adjacent to the Mission) also contains rotating historical exhibits.
Among San Luis Obispo's historical buildings is the former San Luis Obispo Carnegie Library, located at 696 Monterey Street. The San Luis Obispo Carnegie Library was built in 1905 with a grant of $10,000 from Andrew Carnegie, who funded the establishment of 142 California libraries in the early 1900s. The Romanesque style building was designed by architect W. H. Weeks ofWatsonville, California and was built by contractor Joseph Maino of San Luis Obispo. As one of numerous California public buildings designed by W. H. Weeks, it shares features with Carnegie libraries in nearby Lompoc and Paso Robles. The San Luis Obispo Carnegie building served as the city library until 1955, when a new public library was built at the corner of Palm and Morro Streets. It has been home to the San Luis Obispo County Historical Museum since 1956. The Carnegie Library building is listed on the National Register of Historic Places.
San Luis Obispo's largest and oldest voluntary organization is the San Luis Obispo Chamber of Commerce, which also is the oldest and largest voluntary organization in San Luis Obispo County. *source: Wikipedia.org