Old Sacramento State Historic Park is a cluster of noteworthy, early Gold Rush commercial structures. Historic buildings include the 1849 Eagle Theater; the 1853 B. F. Hastings Building, once home to the California Supreme Court; and the 1855 Big Four Building. Old Sacramento's historical significance comes from it being the western terminus of the Pony Express postal system, the first transcontinental railroad, and the transcontinental telegraph.

Old Sacramento is a California Historical Landmark. The National Park Service named the entire original historic 1850s business district of Old Sacramento a National Historic Landmark in 1965. With over 50 historic buildings, Old Sacramento has more buildings of historic value in its 28 acres than any area of similar size in the West.