Stretching more than 150 miles and cutting through the city that bears its name, the Chicago River divides the Second City into the North Side and the South Side. In 1832, the first bridge across the river was constructed. In 1834, the first moveable bridge was erected. Today, Chicago is home to nearly 40 moveable bridges and some 60 bridges in all, making it the most bridge-rich city in the world. The River and its bridges have done much to shape the history of Chicago, which has grown from a rough-and-tumble trading outpost to a world-class city known for its architecture. Chicago's Bridges...