Mitchell Trachtenberg presents a  wonderful talk about the history of Chicago's best-known infrastructure.  Since the city's beginning, moving bridges have been built to cross the river while allowing shipping.  Going through generations of design shifts and re-invention, these causeways became both iconic and infuriating to Chicagoans.

Mitchell is a native Chicagoan and graduate from UIC.  He has long had an interest in Chicago's bridges, their engineering, the art in their lines, and how their design changed to bring us to the present.  Most recently he led tours for the McCormick Bridgehouse Museum and currently works in transportation planning.