Calatrava’s “Chicago Spire”: North America’s Tallest Skyscraper? Andy Towle April 23, 2007 With an endorsement from the Chicago City Planning Commission last week, Santiago Calatrava's 2,000 ft. "Chicago Spire" has come one step closer to … [Read more...] about Calatrava’s “Chicago Spire”: North America’s Tallest Skyscraper?