Nice Madison, I like those little guys. GB is correct, they are a small late prehistoric point from the Mississippian Culture. They are named after Madison Co., Illinois and are found through out the Mississippian River drainage area.
That's cool. I lived most of my life in st Clair county which is the county just south of Madison county and Cahokia mounds is located in Madison county. I ran the mounds a few weeks ago and it's an awesome place! Mad co is also the lawsuit capital of the world!