Collection of the National Building Museum

Before they queued up at Epcot theme park, Americans eager for a glimpse of the future thronged to world’s fairs. Six were held in the U.S. during the 1930s; major corporations and the federal government (often working with leading designers) used them to unveil new technologies and ideas. Designing Tomorrow: America’s World's Fairs of the 1930s, at the National Building Museum in Washington, D.C., assembles more than 200 artifacts, from guidebooks to a giant Westinghouse robot, Elektro the Moto-Man. Through July 10. •