Chicago, that city of broad shoulders, is as Cartesian a city as can be imagined (excepting, perhaps, Salt Lake City). With eight blocks to a mile, and 60 house numbers to a block, any address can be reduced to a set of x-y coordinates. Indeed, there are Chicago street guides that do just that.
The origin is located at State and Madison. Miles are marked off west of State St. by Halsted (800W), Ashland (1600W), Western (2400W), Kedzie, Pulaski, Cicero and Central. All of these avenues run North & South, pretty much the entire length of the city.
East-West streets mark the miles north of Madison, to wit: Chicago, North, Fullerton, Belmont, Irving Park, Lawrence, Bryn Mawr, Devon & Touhy. South of Madison the streets are numbered, and leaving out the first few, one has 31st St., 39th St., 47th St., etc. One has to subtract 7 from these numbers before dividing by 8, to get the number of miles from Madison St. Thus 79th St. is nine miles south of Madison.
The longest street in Chicago is Western Avenue (2400 W), which spans the city from the southern limit at about 119th St., to the northern boundary at Howard Ave. (7600 N). Do the math – it is 22.5 miles long. By legend, Western Avenue is exactly one mile West of Ashland, and one mile East of Kedzie. It also runs due North & South.
But of course that can’t be true – as any school child learning about the Mercator projection surely knows. 22.5 miles is long enough for the curvature of the earth to be measurable – and hence Western avenue is either one mile from Ashland, or it runs due North. For if it runs due north, it will get closer to Ashland in the North, or if it stays a mile away, it must indeed run slightly northwest. I don’t know what the truth is – is there a Chicago buff out there who knows the answer?
Either way, it appears as though the city’s broad shoulders get a little narrower on the North Side of town. I guess that’s why all the Lakefront Liberals live up there. Or maybe it’s why the Cubs always lose.