The structure was completed between 1860 and 1874, designed by architect Reuben S. Clark of Clark & Kenitzer, one of San Francisco's oldest architectural firms, founded in 1854.[5][6] Although not generally considered earthquake country, Sacramento was hit by two earthquakes within days of each other in 1892 which damaged the Capitol.[7] The Capitol was remodeled, adding seventy rooms and elevators, between 1906 and 1908.[8]

Between 1949 and 1952, the Capitol's apse was demolished to make way for the building's expansion with the construction of the Capitol Annex adjoining the historic Capitol building to its east.[9] The offices of the governor of California were housed in the Capitol Annex.

The Capitol and grounds were listed on the office of the National Register of Historic Places in 1973,[1] and listed as a California Historical Landmark in 1974, with a re-dedication on January 9, 1982, to commemorate the close of the bicentennial restoration project.[10][11] The building underwent a major renovation known as the California State Capitol Restoration, from 1975 until 1982, involving an architectural restoration and structural reconstruction for earthquake safety.[7]

In 2012, many protesters stormed the building and were arrested.[12]

The Capitol Annex was vacated in 2021 in preparation for its demolition and replacement with a new Annex on the same site, due to its obsolescence and decayed state.[13][14] Demolition was delayed until 2023 by lawsuits about the project's environmental impacts to the trees in Capitol Park, which is immediately adjacent to the Annex site.[13][15] The offices and personnel previously in the Annex moved into the newly constructed Capitol Annex Swing Space building until the new Annex is constructed.[16][17]