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 supply store occupied one of the smaller storefronts for over twenty years. At one point the building's upper floors, originally intended for office space, were divided into seven apartments. On August 3, 1982, it was added the National Register of Historic Places. As of 2005 the building housed a religious bookstore and a real estate office. In 2015 the building was purchased by Local attorney Sim Osborn and his wife Monica Hart, the couple bought the building with plans to preserve its historic features and aesthetics for future generations. History Joshua Sears Building The Joshua Sears Building is a historic