Louis Sullivan, born in Boston in 1856, entered MIT’s architecture program at 16 and left within a year. After working for Frank Furness in Philadelphia until the Panic of 1873, he went to Chicago, then rebuilding after the 1871 fire, worked briefly for William LeBaron Jenney, and spent a year at the École des Beaux-Arts in Paris. In 1879 Dankmar Adler hired him, and within a year they were partners: Adler the engineer, acoustics pioneer, and dealmaker, Sullivan the visionary. Their Auditorium Building of 1889 combined a 4,200-seat theater, a hotel, and offices. As steel frames freed tall buildings from thick masonry, Sullivan gave them a look: a base, a vertical shaft of piers, and a crowning cornice.

His 1896 line that form ever follows function meant beauty growing from purpose, not bare boxes, and his terracotta and cast iron ornament on the Carson Pirie Scott store showed it. Then came the 1893 World’s Columbian Exposition, where Daniel Burnham’s classical White City launched a national craze Sullivan said set architecture back 50 years, despite his gold-arched Transportation Building winning French medals. The Panic of 1893 followed, the partnership ended in 1894, and Sullivan’s temper, drinking, and failed marriage left him broke. He died in 1924 in a Chicago hotel room, and many of his buildings were later demolished, including the Chicago Stock Exchange, where preservationist Richard Nickel was killed in 1972.

• Why architects first stacked Renaissance, Greek, and Gothic styles on steel-framed towers like a wedding cake
• The jewel box banks of 1907 to 1919 in towns like Owatonna, Minnesota and Grinnell, Iowa
• His reported pitch in Owatonna: a thousand architects could design those buildings, only I can design this one
• Frank Lloyd Wright, fired in 1893 for moonlighting, who still called him Lieber Meister and helped him in the 1920s
• Ayn Rand’s Henry Cameron in The Fountainhead, and the Stock Exchange arch and trading room now at the Art Institute