Why are there only 27 states on the back of a 5 bill?

According to the Bureau of Engraving and Printing there are only 26.

If you think about it for a minute, the names of the states are engraved all the way around the top of the Lincoln Memorial. The back of a bill is a flat picture so it can only show one side of the building. The only way you could see all the way around it would be if the Treasury borrowed some of those moving paintings from Harry Potter's world!