Union City is a city in the San Francisco Bay Area in Alameda County, California, United States located approximately 20 miles south of Oakland, 30 miles southeast of San Francisco, and 20 miles north of San Jose. Incorporated in 1959, combining the communities of Alvarado, New Haven, and Decoto, the city has approximately 75,000 residents and very diverse population. Alvarado is a California Historical Landmark (#503). The city celebrated its 50th Anniversary in 2009. The cities of Fremont, Newark, and Union City make up the Tri-City Area to the south. The larger city of Hayward surrounds the city to the north. Union City and Hayward host many local events and opened a new Teen Center for the youth. In 2017, Union City started to rebrand and got a new city seal.