This street honors Spanish expat Eulogio de Celis (?-1869), who had owned nearly the entire San Fernando Valley in the mid-19th century. Celis Street was christened by 1887 – although in a 1960 interview, Catherine Egbert Dace (1886-1961), granddaughter of San Fernando founder Charles Maclay, suggested that Maclay had named this street around 1880, give or take a couple years. (If true, I don’t know why he dropped the “de” from de Celis.) For more about Eulogio de Celis and his family, see De Celis Place.