Aon Center (Chicago) Aon Center (Chicago) The Aon Center (200 East Randolph Street, formerly Amoco Building) is a modern supertall skyscraper in the Chicago Loop, Chicago, Illinois, United States, designed by architect firms Edward Durell Stone and The Perkins and Will partnership, and completed in 1974 as the Standard Oil Building. With 83 floors and a height of 1,136 feet (346 m), it is the third tallest building in Chicago, surpassed in height by the Willis Tower, and the Trump International Hotel and Tower. The building is managed by Jones Lang LaSalle, which is also headquartered in the building. Aon Center formerly had
Joshua Sears Building works on what is now Peter Kirk Park. The building originally intended to house a bank at the corner. Sears outfitted the entire interior and even hired a partial staff but with the arrival of the Panic of 1893, the doors, like the steel mill, never opened. In the years after the bust, the building, like many others in the area remained mostly vacant, though it, along with a large portion of the original townsite remained in the ownership of the Sears estate. The corner space was eventually occupied by a printing company and later a grocery store. An electric