The structure was known as the Sears Tower from its construction until the naming rights were included in a 2009 lease with the Willis Group.
Several versions of Hals’ portrait of Descartes are known, though Hals has painted only one of them and the rest are copies. One of those copies hangs in the Louvre. For a long time, the Louvre thought that they owned the original portrait by Hals, but nowadays the majority of art experts believes that the original is in the Statens Museum for Kunst in Copenhagen.