Work on the Capitol began in 1860 and was not finished until 1874. It was designed by a small group of architects, and the version you see is credited to Reuben Clark of a San Francisco firm.
The building kept changing. A remodel in 1906 to 1908 added seventy rooms and elevators. In 1949 to 1952 the rounded back of the building, called the apse, was torn down to make room for a new Capitol Annex.
From 1975 to 1982 the Capitol went through a major restoration, including work to make it safer in an earthquake. It was rededicated on January 9, 1982. Today the building also holds the State Capitol Museum, with the historic offices of the governor and the legislature.