Mayor of Los Angeles, California. He received notoriety in the 19th century by serving three times as mayor of Los Angeles, California: from May 9, 1859 to May 9, 1860, from January 7, 1861 to May 6, 1865, and again May 8, 1867 to August 8, 1867. With his French ancestry and being a Democrat, he served a total of almost five years and eight months. During his term, he faced the economic impact of the American Civil War in the east, an epidemic of measles, and flooding after heavy rains. He migrated from Canada to New Orleans, Louisiana, where he became a gambler. Following a stay by way of Mexico during the Mexican War, he came to Los Angeles in 1853. While serving as Water Overseer of the City of Los Angeles, he and his partner, Jean-Louis Sainsevain, laid wooden water pipes under the city's street, which burst flooding the streets and causing muddy sinkholes. He served as Water Overseer from May 12, 1866 to May 8, 1867 and from August 8, 1867 to January 20, 1868. He had partnered with Victor Beaudry in the ice business and mining. Not being able to cope with the financial ruins of this professional disaster and troubles with his personal life such as alcoholism, gambling, and mounting debts, he shot himself in the head while in the Council Room of the Los Angeles City Hall. He did leave his wife, Mary, a letter. Later, his wife remarried for a fourth time to Mr. Teodoli. A commemorative plaque to honor this forgotten mayor can be found outside the Mexican Consulate and Hispanic Cultural Center, yet the dates of his service on the plaque are said to be incorrect. Located in Chinatown, Marchessault Street was named in honor of him, but the street was rename to East Sunset Boulevard in the first half of the 20th century. He was originally buried in , Los Angeles City Cemetery, which is now a defunct cemetery, but later, his remains were moved to Rosedale Cemetery and buried in his wife's plot. His surname has several spellings including “Marchesseault,” which is on his grave marker and in his obituary and “Marchessault,” which was the street spelling.