The story
2020 census
As of the 2020 census, Union City had a population of 70,143. The median age was 39.6 years. 19.1% of residents were under the age of 18 and 16.9% of residents were 65 years of age or older. For every 100 females there were 99.1 males, and for every 100 females age 18 and over there were 96.8 males age 18 and over.
100.0% of residents lived in urban areas, while 0.0% lived in rural areas.
There were 21,432 households in Union City, of which 36.2% had children under the age of 18 living in them. Of all households, 60.6% were married-couple households, 13.8% were households with a male householder and no spouse or partner present, and 21.3% were households with a female householder and no spouse or partner present. About 14.2% of all households were made up of individuals and 6.3% had someone living alone who was 65 years of age or older.
There were 21,911 housing units, of which 2.2% were vacant. The homeowner vacancy rate was 0.5% and the rental vacancy rate was 3.0%.
History
Costanoans ("coastal peoples") were the first inhabitants, primarily the Ohlone peoples living alongside the Alameda and Dry Creeks. Shell mounds along the sloughs of Alameda Creek near the Alvarado sugar mill contained burial sites.
The first non-native community was founded in 1850 by John and William Horner, who named it "Union City" after their Sacramento River Steamship, "The Union". In 1854, it merged with the nearby community of New Haven (founded 1851) to form the town of Alvarado, named after a former Mexican governor, Juan Bautista Alvarado. Alvarado was the first county seat of Alameda County, a designation it lost in 1865 to San Leandro. Further east, Decoto was founded in 1870 as a railroad hub, hosting the first transcontinental railroad. Alvarado-Niles Road, one of the city's largest streets, connects the historical Fremont district of Niles with the historical Union City district of Alvarado.
The California Beet Sugar Company, the US' first successful sugar beet mill, was located in Alvarado and began operations in 1870. The plant was demolished in 1977.
Union City is a former railroad and steel town with an extensive industrial heritage. The Pacific States Steel Company occupied the land behind Union City Station that is redeveloping into the Union City Station District Downtown. The Alvarado and Decoto neighborhoods were both former railroad hubs and active railroad lines bisect both East End and the West Side of town. Trains are a way of life in Union City and natives are accustomed to waiting for Amtrak and freight trains to cross while commuting.
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In the 1950s, Alvarado and Decoto – the latter making up the eastern side of the town – were annexation targets of the nearby communities of Newark, Hayward, and what would become Fremont. On January 13, 1959, they decided to incorporate into a single city, and named it after the Horners' original settlement, Union City. Tom Kitayama served as the city's first mayor in 1959 and was involved in Union City politics until his 1991 retirement. The population grew from 6,000 in 1959 to 70,000 in 2020. In 2016, Union City started to rebrand and unveiled a new city seal. Union City opened a new Teen Center in 2018. In March 2025, the city of Union City rolled out new city branded color coded trash carts with Republic Services and local Tri-CED community recycling to meet state and local goals.
From Wikipedia’s article on Union City, California, shared under CC BY-SA 4.0.4