In 1842, James Fitch, Orasmua Bushnell, and Charles Butler of the American Land Company donated a three-acre parcel to the city for use as a public park. The donors named the site Washington Square, possibly after a similar park located in an elegant New York City neighborhood. As the developers had hoped, Chicago's Washington Square was soon surrounded by many fine residences and churches. In 1869, the city began improving Washington Square with lawn, trees, bisecting diagonal walks, limestone coping, and picket fencing. By the 1890s, an attractive Victorian fountain adorned the square. Within a decade or so, however, it had been razed and the park had deteriorated. In 1906, when Alderman McCormick became President of Drainage Board, he decided to devote his aldermanic salary to improving the park. McCormick donated a $600 fountain, and the city allocated an additional $10,000 to rehabilitate the park. Landscape improvements were planned by the renowned designer, Jens Jensen, then a member of the board of the city's Special Park Commission.

By the 1910s, the neighborhood surrounding Washington Square had become more diverse. Because many old mansions were converted into flophouses, the park earned the nickname, "Bughouse Square." Like Speakers' Corner in London's Hyde Park, Washington Square became a popular spot for soap box orators. Artists, writers, political radicals, and hobos pontificated, lectured, recited poetry, ranted and raved. A group of regulars formed "The Dill Pickle Club," devoted to free expression. For years Washington Square orators appointed their own honorary "king." In 1959, the city transferred Washington Square to the Chicago Park District. Although Alderman McCormick's fountain was removed in the 1970s, in the late 1990s, the park district, the city, and neighborhood organizations agreed on a restoration plan for Washington Square. Improvements include a reconstructed historic fountain, period lighting, fencing, and new plantings.