The Industrial Revolution gave architects many new materials to build with, like iron and steel, concrete and strong glass. In 1779 English ironmonger Abraham Darby built the first iron bridge over the river Severn. It proved that cast iron could be used as A strong building material. The Crystal Palace that Joseph Paxton put up at the Great Exhibition in London in 1851 was entirely made of glass and iron. Modern architecture became widespread in the twentieth century. It was much simpler than the ornamental style of the past. Buildings were more practical and designed to make the most of space.