Professor Edward J. de Smedt invented modern road asphalt in 1870 at Columbia University in New York City after emigrating from Belgium. He patented it and called it "sheet asphalt pavement" but it became known as French asphalt pavement. Because a natural rock known as asphalt had been used to construct buildings for many years. In 1824 large blocks of natural asphalt rock were placed on the wide boulevard in Paris known as the Champs-Élysées. This was the first time this type of rock was used for a road.