The first official World’s Fair to be held in the United States commemorated the 100th anniversary of the nation’s independence and turned Philadelphia into a hotbed of culture and innovation. A number of world-changing inventions debuted at the 1876 Centennial Exposition, but probably the biggest was the first public showing of Alexander Graham Bell’s telephone. Bell had just patented the device, and set it up in the huge Machinery Hall. At one end, a bearded man spoke into the horn, and fair officials were startled to hear his words come out, clear as day, from a speaker at the other end. It was the talk of the fair, and revolutionized communications as we know them.
Photo credit: Illustrated London News