[4] The Georgia General Assembly incorporated Union City in 1908.

[5] One source claims that the town was named for the union of rails at a railroad junction,[6] while another version states the name commemorates a "Farmer's Union" which once was headquartered here.

As of the 2020 United States census, there were 26,830 people, 8,088 households, and 4,681 families residing in the city.

Males had a median income of $30,421 versus $28,111 for females.

Union City is in the Fulton County School District.