In October of 1901, one month after the assassination of William McKinley, 25th President of the United States, the South Park Commission (SPC) officially named a new and still undeveloped park in his honor. Experimental in its location and intent, this park proved to be nationally important. At the time, Chicago's existing parks were far away from the filthy, noisy, overcrowded tenement neighborhoods in the center of the city. Superintendent J. Frank Foster envisioned a new type of park that would provide social services as well as breathing spaces in these areas. To test the idea, in 1901 the park commission began acquiring property near the Union Stockyards. Composed of open prairie and cabbage patches, the site had previously been the Brighton Park Race Track. The experimental McKinley Park originally offered ballfields, lawn tennis, swimming and wadinglagoon, and a lovely classically-designed bathhouse. More than 10,000 people attended the park's dedication on June 13, 1902. The effort was so successful that the following year the South Park Commission began creating a whole system of new neighborhood parks for the south side. Opened to the public in 1905, the first ten were: Sherman, Ogden, Palmer, Bessemer, and Hamilton Parks, and Mark White, Russell, Davis, Armour, and Cornell Squares. These innovative neighborhood parks influenced the development of other parks throughout the United States. McKinley Park received such intensive use, that in 1906, the SPC acquired adjacent property, doubling its acreage. The designers expanded the existing wading pool into a large naturalistic lagoon with several small wooded islands. They also introduced a children's playground, a music court plaza, open-air gymnasiums, and the following decade, a field house.