Site last updated June 2020

The county [Alameda County] was formed on March 25, 1853, from a large portion of Contra Costa County and a smaller portion of Santa
Clara County.

The Spanish word alameda means "a place where poplar trees grow," a name which originally was given to the Arroyo de la Alameda (Poplar Grove Creek).  The willow and sycamore trees along the banks of the river reminded the early explorers of a road lined with trees, also known as an alameda.  [see here]

County Courthouse

Located in Oakland, California

The county seat at the time it was formed was located at Alvarado; it was moved to San Leandro in 1856 wherethe county courthouse was destroyed by the devastating 1868 quake on the Hayward Fault.  The county seat was then re-established in the town of Brooklyn from 1872-1875. Brooklyn is now part of Oakland, which has been the county seat since 1873. 

Much of what is now considered an intensively urban region, with major cities, was developed as a trolley car suburb of San Francisco in the late 19th and early 20th centuries.  The historical progression from native American tribal lands to Spanish, then Mexican ranches, then to farms, ranches, and orchards, then multiple city centers and suburbs, is shared with the adjacent and closely associated Contra Costa County.

Biographies are currently being added to the bios page.  Be sure to check them out.  Specifically to
History of Alameda County California - Volume II



  California became a state on September 9, 1850, but it was not until March 25, 1853, that the bill creating Alameda County was approved.  The county derived its name from Alameda Creek, its principal stream, and which had been the dividing line between Contra Costa and Santa Clara counties.  The creek, lined with trees through the otherwise sparcely [sic] wooded plains, gave it the resemblance of a shady walk or road, which in Spanish is called an alameda.  When the Mexican pioneers discovered this section of the state they knew it b the name of the place of the alameda.  It is not known exactly what the population of the county was at the time of its creation.  In 1862 a second census was taken of Contra Costa County, and its entire population, including the portion secured by Alameda County in 1853, was but 2,750.  However, William Halley, who wrote his history of county in 1876, estimated the population of Alameda County in 1853 at about three thousand, which, he admits, was a considerable increase over the population of two years previous, when it was credited with 752.  The act creating the county reads as follows:  [see more]

From:  History of Alameda County, California, by Frank Clinton Merritt, Chicago, Ill.: S.J. Clarke Pub. Co., 1928, 1276 pgs.; pgs. 

 Adjacent Counties -- Wikipedia

Alameda County was originally hosted by Laurel Egenberger, who was the Web Maven from 1998 - 2004.

Cat Nielsen was Web Maven from 2004 to 2012 - Thanks Cat for a job Well Done

Thank you to the prior Alameda County coordinators for the information and materials they have provided, and for their years of service to Alameda County, CAGenWeb.  All of their contributions and dedication are truly appreciated.