 The 1939 New York World's Fair, marking the 150th anniversary of George Washington's inauguration in Federal Hall, was a high point of technological optimism, meant to mark the end of the Depression.After the start of World War II, though, the theme was changed from "Building the World of Tomorrow" to "For Peace and Freedom", and the shadow of the war underway in Europe dampened the proceedings.The economy of New York City was boosted by the war effort, but not to the extent of cities with heavy industries such as Pittsburgh, Chicago, Los Angeles or Detroit.