Widely acknowledged as one of the 20th century's most important and influential American architects, Louis Sullivan is considered by many as "the father of modern architecture." Espousing the influential notion that "form ever follows function," Sullivan redefined the architectural mindset of subsequent generations. Despite this seemingly stark dictum, Sullivan is perhaps best known for his use of lush ornament. Natural forms were abstracted and multiplied into until recognizable only as swirling linear elements.
In 1893 Sullivan and his partner Dankmar Adler earned the commission of the Chicago Stock Exchange Building located on Lasalle Street. The first floor and second floor's main trading room was the centerpiece of the building and received the most attention. Richly colored and densely patterned, the trading room was a broad, open space as dictated by its use. Stenciled panels and leaded glass skylights created a canopy of color over the room.
After much public outcry, the Chicago Stock Exchange was demolished in 1972. Luckily, the Art Institute of Chicago installed the majority of Trading Room and the massive entrance arch to the Stock Exchange so that future generations could appreciate this master work of Sullivan's career.