Shown here is an artist’s rendition of the Centennial Tower for the Philadelphia Centennial Exposition of 1876 as it appeared on the cover of the January 24 1874, edition of Scientific American.

In order to show their readers the magnitude of the tower, the artist engraved and grouped in the background what were the highest structures in the world at that time, which included the Great Pyramids of Cheops and Cephren, Cologne’s famed cathedral, St Peter’s Cathedral, St. Paul’s Cathedral, the U.S. Capitol dome, the steeple of New York’s Trinity Church, the Bunker Hill Monument, and St. Mark’s Church in Philadelphia.

Clarke, Reeves & Co., owners of the Phoenixville Bridge Works of Phoenixville, PA, designed the tower. Drawings showed the central tube to be 90 feet in diameter with a spiral staircase and four landing and viewing platforms with the last being a magnificent observatory at the top of the 1000-foot high tower. At nighttime it would be brilliantly illuminated.

Thus, as Scientific American reported, the 100th birthday of the United States would be commemorated by the tallest structure ever built by man, built by American engineers and mechanics on American soil and constructed of material purely produced in America.

It was estimated that nearly 10 million people came to tour the magnificent sites and exhibits of the 1876 Philadelphia Centennial, which was over fifth of the population of the United States at that time. But none of them climbed or viewed the Centennial Tower, as it was never built.