 His Wainwright Building (1891) features strong base-pediment-shaft massing and an insistently vertical pattern of ornament; his Union Trust Building of 1893 was stripped of its cave-like street-level ironwork in 1924.Beyond Sullivan's work, other significant downtown skyscrapers of those years were Railway Exchange Building (1913) by John Mauran and the now-demolished Merchants Exchange Building.Some warehouse and factory buildings of the early 20th century have been transformed into local attractions, such as the International Shoe factory building and its renovation into the St. Louis City Museum.