On February 25, 1901, people asked the City Council to make a park on King William Street. The Council said yes on June 3, 1901, and suggested buying the triangular lot at King William, Turner, and Washington Streets for $4,208.50 from Mrs. P.H. Groesbeck. The Council named it "King William Place," and the City Engineer put that on the maps.
A few months later, the Council okayed spending money to fix up the area and put water pipes in the park. Landscaping likely happened next, but we don't know the details. In 1917, an article in the San Antonio Express called it "King William Park." In old pictures around 1920, the park looked a bit landscaped, and later, trees were planted around the edges.
The park's gazebo was once in the United States Arsenal grounds near the Commander’s House. In 1954, the King William Area Conservation Association moved it to the park. They fixed it up in 1987.