A group of researchers were doing a search of public records for evidence of government corruption, and ran across what is to believed to be the oldest authentic copy of the Constitution on record.  On this copy of the Constitution, printed in 1825, the 13th Amendment shown has nothing to do with slavery.  It's intent was to prohibit lawyers from serving in government capacities.  This is a series of articles that are mostly very short.  The site has 2 opinions of this original 13th.  Here is the link:

http://www.civil-liberties.com/13/index.html