"That someone is legendary blues musician Son House. Son said he knew for a fact where Johnson made his deal, and it wasn't in Clarksdale, but in Rosedale. In fact, he claims in was right where Hwy 8 intersects with Hwy 1. That's the real crossroads, he says."

from

http://www.tdblues.com/2008/03/the-real-crossroads/