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
Wachovia Tower (Baltimore) Tower rises from the site formerly occupied by the Calvert Building and 7-9 Saint Paul Street. The building, formerly housing offices for Wachovia, is now home to the regional office of Wells Fargo and Company. Wachovia Tower (Baltimore) The Wells Fargo Tower, formerly known as the First Union Signet Tower, Wachovia Tower, and Union Trust Building, is a commercial high-rise in Baltimore, Maryland. The building rises 24 floors above street level and is in height; it is tied with Charles Center South as the 17th-tallest building in the city. The structure was completed in 1985. The Wells Fargo Tower was