European exploration recorded and mapped some of the San Francisco area from 1542 onwards. Sir Francis Drake cruised by the general area in 1579.
In 1769, Ortega mapped and reported the entrance to San Francisco Bay. In 1776, Spanish missions and military garrisons began moving into the area. The Mexican War of Independence from 1810-1821 established Mexico's (and thus Alta California's) independence from Spain.
By the 1820s, U.S. ships were regularly visiting the Mexican port of San Francisco.
Then there was the Mexican American War in 1845 or so, resulting in the U.S. annexing about a third of Mexico including California. With the Gold Rush in 1849, San Francisco was established as a major town with thousands of residents. Sand dunes and marshes were quickly filled in as real estate boomed. Legal battles over land with the Mexican land grant and ranch owners continued even into the 1900s. Chinese immigrants came in huge numbers in the 1850s-1880s, building railroads and working in mines, until the Chinese Exclusion Act of 1882.
Joshua A. Norton issued proclamations declaring himself Emperor in 1859 and was a charismatic figure in the town until his death in 1880.
The 1906 Earthquake and Fire ... Angel Island opens as immigration processing center, 1910... Pacific Exposition and Palace of Fine Arts 1915... Influence of WWI on the area... Great Highway built in the 1920s finished 1929... Depression, strikes, unions, immigration in 1920s... Bay Bridge built in 1936... Golden Gate Bridge built 1937 ... WWII . . . Japanese American Internment ... beat poets ... The Diggers... LSD and Summer of Love... the occupation of Alcatraz Island... civil rights activism and protests... occupation of the Federal Building over the ADA... AIDS and HIV ... Harvey Milk... Loma Prieta Earthquake... influence of Silicon Valley on the area and the town.