Completed in 1889, Dankmar Adler and Louis Sullivan's Auditorium Building was the largest building in the world, "as important a building for nineteenth-century Chicago as Brunelleschi's cathedral cupola had been for fifteenth-century Florence," writes historian Don Miller.

The landmark Auditorium, where Theodore Roosevelt delivered his famous Bull Moose speech in 1912 and anti-Vietnam War protestors and police clashed outside the Democratic national convention in 1968, still stands today.