The city purchased this property above downtown Seattle for a park in 1876. Beginning in the early 1890s, Seattle’s first superintendent of parks, architect and engineer E.O. Schwager, made minor improvements to the park. In 1901 the name Volunteer Park was adopted to honor veterans of the Spanish-American War, and the city’s first reservoir was built on the site. A water tower was added in 1906, with guidance from landscape architect John Charles Olmsted on its placement, style, and potential for future use as an observation deck. In 1903 the Olmsted Brothers firm was engaged by the city, during which time John Charles Olmsted spent several weeks studying Seattle’s open-space potential. His report, entitled A Comprehensive System of Parks and Parkways, was accepted by the city that October and included recommendations for Volunteer Park.
The 1909 design for Volunteer Park implemented an integral element of the Olmsted Brothers' plan for Seattle's parks and boulevards. The design included both formal and pastoral elements, such as circuit paths and drives, lily ponds, a wading pool and playground, a pergola/music pavilion, shelter and comfort stations, and an allée linking the water tower and a small conservatory. In 1933 the Seattle Art Museum opened in the center of the park, replacing the pergola and music pavilion. Other additions include a granite boulder to honor Spanish-American War veterans in 1952, a play sculpture by Charles Smith in 1962, and the Black Sun sculpture by Isamu Noguchi in 1969. The park was listed in the National Register of Historic Places in 1976.