Conceived in 1860 on four blocks adjacent to the California State Capitol building in downtown Sacramento, this park features hundreds of trees from around the world. By the early 1870s, the landscape was regraded and terraced using silt from the bed of the Sacramento River, and geometric paths were laid out to connect planting beds. William O’Brien, first State Capitol Gardener, set out to develop a landscape with dozens of trees from “every nation on earth.” Under the guidance of the Capitol Park Commissioners, O’Brien surveyed and designed the grounds, which were completed concurrently with the Capitol building, constructed between 1861-74. In 1884 a pavilion and race track were constructed to host state fairs; the site of the pavilion is now host to native California plants.
By 1908 the park included more than 800 specimens representing 80 tree species, many the first planted in a United States arboretum from locations below the Tropic of Cancer. The park's design continued to evolve as it grew over the course of the 20th century to today’s 40 acres across twelve city blocks, including significant renovations in 1948-51. The landscape currently contains 864 trees, including 210 distinct species, some of which are the original plantings from the 1870s, including Deodar Cedars grown from seed imported from China. The park also features a number of memorials, such as the Civil War Memorial established in 1902 by the Ladies of the Grand Army of the Republic. The California State Capitol, including the park grounds, was listed in the National Register of Historic Places in 1973.