Flag of California
Flag of California in the Cerritos ready room
The flag of California was a patriotic banner that symbolized the Earth region of California.
The flag was displayed alongside the flag of the Federation and others behind a panel of admirals at Starfleet Academy in 2258. (Star Trek)
Captain Carol Freeman had a tattered flag of California displayed in a frame on the wall of her ready room on the USS Cerritos. (LD: "Second Contact")