What does "When that Depression-era fair shuttered" mean? "The Ford Rotunda was circular in an automotive manufacturing kind of way. It was shaped like an enormous set of grooved transmission gears, one fitting neatly inside the next, rising first 80 then 90 then 100 then 110 feet, to the equivalent of ten stories. Virtually windowless, with its steel frame and exterior sheath of Indiana limestone, this unusual structure was the creation of Albert Kahn, the prolific architect of Detroit’s industrial age. Kahn had designed it for the Century of Progress exposition in Chicago, where Ford’s 1934 exhibit hall chronicled the history of transportation from the horse-drawn carriage to the latest Ford V-8. When that Depression-era fair shuttered, workers dismantled the Rotunda and moved it from the south side shore of Lake Michigan to Dearborn, on the southwest rim of Detroit, where it was reconstructed to serve as a showroom and visitors center across from what was then Ford Motor Company’s world headquarters." Thank you.