Mark Hersch is know for taking rare, historic photographs of Chicago and other cities and merging them with photographs he takes from the exact same vantage point in the present day. The result of combining them into a single image reveals both parts of the old world and parts of the new. While he has created dozens of what he calls rephotographs of historic images in Chicago, New York, Los Angeles, Boston, San Francisco, and Washington, his talk to members of The Cliff Dwellers not surprisingly focused on Chicago.