There’s a curious temporary display in the atrium at the USPTO. Called “Walk through time”, it is a winding
path with large printed labels on the floor, portraying various events in the history of the USPTO. It starts with the founding of the patent office and proceeds through some sixty or so events to the present. 
My personal favorites are the 1887 event (the US joins the Paris Convention) and the 1970 event (the US joins the Patent Cooperation Treaty).