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 "SEARS". The second entrance is centered on the east facade and bears many of the same features: pressed metal pediments, etc. The Sears Building was built in 1891 by Boston millionaire, philanthropist and Kirkland investor Joshua Montgomery Sears as part of the speculative land boom following Peter Kirk's proposal of building a steel producing mecca that would rival Pittsburgh on the east side of Lake Washington. The building cost $18,000 to build, at the time the most expensive being built in Kirkland outside of the steel mill itself. The bricks were pressed from local clay at Peter Kirk's own brick