Grange Park was originally the front lawn and garden of the Grange, a manor house built in 1820 by the Boulton family, an influential family in 19th century Toronto. In 1910, Harriet Boulton (also known as Mrs. Goldwin Smith) bequeathed her estate to the Art Museum of Toronto (later the Art Gallery of Ontario) which included the Grange, and the surrounding property. On January 20, 1911, the Art Museum of Toronto reached an agreement with the City of Toronto, where the city would maintain the grounds south of The Grange as a municipal public park. The agreement continues to be in force, with the art museum remaining as the property's owner, and the Toronto Parks, Forestry and Recreation Division maintains the grounds as a municipal park.