More than sixty sculptures in a broad range of styles dating from the 1880s through the 1960s are displayed in it, while another dozen sculptures from the 1960s to the 1990s occupy the plaza around the museum building. Together the landscaped grounds form an outdoor gallery that is enjoyed by more than 340,000 visitors annually. In her introductory essay, Valerie Fletcher records the little-known history of the Hirshhorn Museum's garden and plaza,...