48 years ago on May 17th, 1976 The Roosevelt Island Tram opens for business, becoming the first commuter aerial tramway in North America References: Wikipedia
140 years ago on May 17th, 1884 P.T. Barnum leads a parade of 21 elephants across the Brooklyn Bridge
56 years ago on May 17th, 1968 A second round of protests take place at Columbia University, lasting for five days and resulting in 177 arrests