Arrow points, Kingston Lake site, Peoria County.
New forms of arrow points appear during the Mississippian period. These specimens, called Cahokia notched points, are commonly found along the Mississippi and Illinois rivers.

The bow and arrow remained the principal weapon of Native Americans, until it was eventually replaced by increasingly sophisticated firearms in the 18th century. Today, Illinois farmers often find small triangular and stemmed arrow points when they cultivate their fields. Mississippian hunters, and their Native American successors, hunted throughout the state.

The bow and arrow was used mostly for hunting, but there is increasing evidence than it became the principal weapon in human conflict. Osteologists studying the remains of Mississippian people find arrow points imbedded in bones and in other locations that indicate the person was wounded or killed.

Mississippian people also made long, pointed knives, some of which were probably used for ritual purposes. They often used a particular stone from Union County called Mill Creek chert to make these tools. Mill Creek chert knives are found widely distributed in Illinois and neighboring regions.