Chicago’s Street Grid System Was Dreamed Up by a Vacationer in Paw Paw, Michigan

Today Chicago's streets are very logical. The street grid system has its nexus at the corner of State and Madison in the Loop. Street numbers grow sequentially the farther you move from that point.

Chicago's street system wasn't always that way. Their orderly manor is thanks to a nearly forgotten city resident who dreamed up a new scheme while on vacation across the lake in Paw Paw, Michigan.

The story is revealed in a slim and fascinating book on the history and relevance of street numbers called The Address Book by Deidre Mask. In the book, Mask tells the story of Edwin Brennan who worked the streets of Chicago as a delivery man and bill collector in the decades following the Civil War. As Chicago grew, it annexed surrounding towns and took in their street names, many conflicting with existing streets in Chicago.

Brennan desired to make a more logical system so when the family set out for a vacation around Lake Michigan in the southwest Michigan village of Paw Paw, Brennan brought maps. A stack of maps of Chicago from which he determined to reimagine the city's street grid.

His plan was simple: Building numbers start at 0 at State and Madison and grow by 800 every mile you extended out.

The plan was adopted by the city council in 1908 and remains in effect today.

So you won't find any statues or monuments to Brennan around the city, but perhaps the one commemoration of him is the one he'd most treasure, a street bears his name. South Brennan Avenue is a residential street that runs for two short blocks between 96th and 98th Streets on Chicago's south side.

Just a few miles north of Brennan Avenue in Chicago was the beginning of the legendary Route 66. Take a virtual trip down the Mother Road: