[the urban politician]

Originally Posted by Mr Downtown

Most of Chicago (between the Indian Boundary lines) is 1.3 degrees west of true north, for reasons now lost to history. Our area was surveyed proceeding northeastward from Downstate Illinois. The line of reference, Third Principal Meridian, runs due north-south near Decatur, but for some reason a lot of error had crept in by the time they got this far north.

You can view the original surveyors notes online.</a> The surveys all include notes indicating the variation from true north and from magnetic north, so the surveyors were well aware that the grid was skewed; they just didn’t think it was important to spend the time and effort required to run a new true meridian or rangeline. They apparently thought it was more important to make all the townships and sections equal in acreage—and proceed quickly to sale of the new farmland.

Meanwhile, the area southeast of the old diagonal Indian Boundary Line from Lake Calumet along I-57 to Frankfort was surveyed at a different time, as was the area between the Wisconsin line and Central Rd (Rolling Meadows)/Central St (Evanston)—and those surveys are on true north. As a result, ostensibly parallel Golf Road and Central Rd (extended) are nearly 1.5 miles apart in Elgin but only a half mile apart by the time you reach Evanston.

To further complicate things, when James Thompson surveyed Chicago's original townsite in 1830, he set the streets parallel to the Main Stem of the river, meaning that the area in between Kinzie and Madison, State and Desplaines is 1.1 degrees east of true north.

You're like an encyclopedia of Chicago