San Mateo County was formed in 1856 after San Francisco County, one of the state’s 18 original counties since California’s statehood in 1850, was split apart. Until 1856, San Francisco’s city limits extended west to Divisadero Street and Castro Street, and south to 20th Street. In response to the lawlessness and vigilantism that escalated rapidly between 1855 and 1856, the California government decided to divide the county.
According to the U.S. Census Bureau, the county has a total area of 741 square miles (1,920 km2), of which 448 square miles (1,160 km2) is land and 293 square miles (760 km2) (40%) is water. It is the third-smallest county in California by land area. A number of bayside watercourses drain the eastern part of the county including San Bruno Creek and Colma Creek. Streams draining the western county include Frenchmans Creek, Pilarcitos Creek, Naples Creek, Arroyo de en Medio, and Denniston Creek.
The 2010 United States Census reported that San Mateo County had a population of 718,451. The racial makeup of San Mateo County was 383,535 (53.4%) White, 20,436 (2.8%) African American, 3,306 (0.5%) Native American, 178,118 (24.8%) Asian (9.8% Filipino, 9.0% Chinese, 1.9% Indian, 1.2% Japanese, 0.8% Korean, 0.5% Vietnamese, 0.3% Burmese, 0.1% Pakistani), 10,317 (1.4%) Pacific Islander (0.6% Tongan, 0.3% Samoan, 0.2% Fijian, 0.1% Native Hawaiian), 84,529 (11.8%) from other races, and 38,210 (5.3%) from two or more races. Hispanic or Latino of any race were 182,502 persons (25.4%); 15.7% of San Mateo County is Mexican, 2.7% Salvadoran, 1.2% Guatemalan, 1.2% Nicaraguan, 0.7% Peruvian, 0.6% Puerto Rican, 0.2% Colombian, and 0.2% Cuban.
San Mateo County has a five-member Board of Supervisors, representing five geographic districts, elected at-large until November 2012. On November 6, 2012, Measure B passed to amend the San Mateo County Charter so that each member of the Board of Supervisors will cease to be elected by an at-large vote of all the voters in the County, but is instead elected only by the voters of his or her district.
San Mateo County is split between California’s 14th and 18th congressional districts, represented by Jackie Speier (D–Hillsborough) and Anna Eshoo (D–Atherton), respectively.
San Mateo County is split between California’s 14th and 18th congressional districts, represented by Jackie Speier (D–Hillsborough) and Anna Eshoo (D–Atherton), respectively.
A July 2013 Wall Street Journal article identified the Facebook initial public offering (IPO) as the cause of a change in the U.S.’ national economic statistics, as San Mateo County—the home of the company—became the top wage-earning county in the country after the fourth quarter of 2012. The article revealed that the Bureau of Labor Statistics reported that the average weekly wage in the county was US$3,240, which is 107% higher than the previous year: “That’s the equivalent of $168,000 a year, and more than 50% higher than the next highest county, New York County (better known as Manhattan), which came in at $2,107 a week, or roughly $110,000 a year.”