What the heck is 16th Section Land?

I actually ran across some information on the Mississippi Secretary of State's Website about the odd and often maligned 16th Section land. I've sold homes on 16th Section Land before and its never been that big of a deal but it was good to find this information.

Here's the link.

http://www.sos.state.ms.us/PublicLands/16th/16l_faq.asp#a2