California Historical Landmarks in San Francisco
California Historical Landmark 623
Union Square
Geary and Powell Streets
This was the center of San Francisco in pioneer days, deeded for public use January 3, 1850 during the administration of John White Geary, first mayor and postmaster, and later Governor of Kansas and Pennsylvania. The name originated in 1860 when public meetings were held here in support of the Union.
Citation from California Office of Historic Preservation