Aon Center (Chicago) the world headquarters of Aon and Amoco. Aon's US operations are still headquartered here. The building is also the co-headquarters of Kraft Heinz. The Standard Oil Building was constructed as the new headquarters of the Standard Oil Company of Indiana, which had previously been housed at South Michigan Avenue and East 9th Street. When it was completed in 1973, it was the tallest building in Chicago and the fourth-tallest in the world, earning it the nickname "Big Stan". (A year later, the Sears Tower took the title as Chicago's and world's tallest.) The building employs a tubular steel-framed structural system
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