Stephen Clark Foster (December 17, 1820 – January 27, 1898) was a politician, the first American mayor of Los Angeles under United States military rule. Foster served in the state constitutional convention, and was elected to the State Senate. He was elected as mayor of Los Angeles in 1856, and later elected for four terms to the Los Angeles County Board of Supervisors. Early life and education Foster was born in Machias, Maine, December 17, 1820. He graduated from Yale College in 1840. Career He taught at a private academy in the South. In 1845 at age 25, he headed for California, like many other young single men, via El Paso and Santa Fe. While in Santa Fe, Foster was hired by Quartermaster Wm. M.D. McKissack to be an interpreter for the Mormon Battalion of Volunteers, then on its way to California as part of the Mexican–American War forces sent to California. He acted unofficially as an additional guide. In the stormy period when California was under US military rule after the defeat of the Mexicans, Governor Richard Barnes Mason appointed the 26-year-old Foster alcalde (mayor) of Los Angeles to replace the dissolved ayuntamiento (government) of the Mexicans. For this reason, Foster often has been referred to as the first American mayor of the city. He served as alcalde from January 1, 1848 to May 21, 1849. For the remainder of that year, or until the city came under United States jurisdiction in 1850, Foster served as prefect. Mason appointed José del Carmen Lugo, a prominent and mature Californio, as mayor following Foster. Marriage and family During his early years in Los Angeles, Foster made a marriage important to his standing in the community. He met and married María Merced Lugo, one of the sisters of José del Carmen Lugo above. Their father was a prominent Californio landowner. The Fosters had five children together. Foster was elected a member of the 1849 California Constitutional Convention, which met in Monterey. The group framed the state Constitution and petitioned Congress for admission of California into the United States. Political career Foster achieved his first political office after statehood in 1850, when he was elected to the Los Angeles Common Council for a one-year term. In 1851 he was elected California state senator from Southern California, and served two years. In 1854, Foster was elected mayor of Los Angeles. He is credited with