How about this:
http://en.wikipedia.org/wiki/Indiana_Pi_Bill
Sorry it requires some reading... However the first section summarizes it, but you should still read the wikipedia pages:
The Indiana Pi Bill is the popular name for bill #246 of the 1897 sitting of the Indiana General Assembly, one of the most famous attempts to establish scientific truth by legislative fiat. Despite that name, the main result claimed by the bill is a method to square the circle, rather than to establish a certain value for π, although the bill does contain text that appears to dictate various incorrect values of π, such as 3.2.
The bill never became law, thanks to the intervention of a mathematics professor who was incidentally present in the legislature.