Although true blade technologies were virtually unknown throughout the entire Archaic period of the American Midwest, they blossomed briefly during the Middle Woodland, but died out and were absent again during the rest of prehistory. Despite their temporal specificity, we have no idea why this technology developed. In the most intensive attempt so far to derive an answer to this question, Yerkes, at the Murphy site in Ohio, was able to conclude only that blades were used for a variety of tasks, just like bifaces or retouched flakes.
My own research sheds light on this problem, at least in the lower Illinois Valley of Illinois. I have applied intensive use-wear analyses to three Middle Woodland components: the Smiling Dan settlement and two different kinds of ceremonial manifestations from the Napoleon Hollow site. Bladelets were used very differently in these three situations. At the habitation they were relatively unimportant and were used for a variety of tasks, just as at the Murphy site. But in mortuary contexts they were numerically very significant and were employed for a restricted range of tasks—primarily for cutting and scraping soft materials. This conclusion suggests that the blade was an integral part of Hopewell ceremonialism.