The Capitol was designed by Reuben S. Clark and completed between 1861 and 1874, based on the US Capitol in Washington. A dome 210 feet high carries a lantern capped by a gold-leafed finial. The Legislature has met here since 1869.
It was listed on the National Register of Historic Places in 1973 and underwent a major restoration from 1975 to 1982, including earthquake strengthening. The basement and first floor of the original section now form the California State Capitol Museum, with restored historic offices and exhibits.