In many ways, Sullivan’s buildings did break from tradition. Instead of a series of tiny Italian cupolas, one on top of the other, Sullivan demanded unified structures proud of their own height. By stripping excess ornamentation from the upper reaches of his designs, he emphasized the verticality of the buildings, which resembled obelisks. And while many architects imposed their signature style on every building they designed, be it an opera house or an office building, Sullivan favored tailoring each new design concept to its use case. He didn’t always follow his own advice. While he had a rebellious streak, he couldn’t escape the influence of European history entirely; in art and architecture, nothing is truly new. Just as the Transportation Building featured Romanesque details—cathedral arches, Italianate copulas, and sculpted angels—his most provocative works drew on what he knew. Sullivan’s National Farmers Bank in Owatonna, Minnesota, for example, may be a brick “jewel box” monolith, but it’s defined by enormous green stained glass windows, a hallmark of European religious architecture going back at least 1,300 years.