Did some sort of massacre or multiple murders occur near 18th and Prairie Ave very early in Chicago's history?

Answer 1

Yes, it was the site of the Fort Dearborn Massacre in the early 19th century, where a monument stands today. More info can be read here: virtualchicagoland.com

I have read that the massacre took place at 16th and Indiana. That's very close I imagine. Stories have it that The soldiers who came to reoccupy the fort four years later found bodies strewn through the dunes. Bones have been reported to be unearthed around there in early street building days.

See the related question link to the right:

Actually I went to the site in October 2005 and the monument is not there now. (I heard later that there are plaques on nearby buildings, but didn't notice on my visit.) Did some research (that hopefully will help correct the reference on the Chicago Historical Society's encyclopedica site) and learned it was moved to the nearby Hillary Rodham Clinton Park on Prairie, then put into storage by the Chicago Park District according to a 1998 newspaper article. I'm checking that out now.