Shaped by History

Jenny Price asks Mark Stein why Wisconsin is shaped like a mitten. Mr. Stein is author of How the States Got Their Shapes and Ms. Price interviews him in the alumni magazine On Wisconsin, Winter 2008.

(Actually lower Michigan is shaped like a mitten, and Wisconsin is shaped like a handprint. One explanation is that these are each Paul Bunyan's hand print, one with a mitten on, the other with it off.)

Mr. Stein says Wisconsin's shape resulted from a chain reaction of losses to territories that became states earlier, and the belief that other states should have access to a Great Lake. The former lead to the Upper Peninsula being added to Michigan. The latter prevented the Wisconsin's boundaries from running through Chicago and the Twin Cities.

John Lindquist summarizes the Evolution of Territories and States from the Old "Northwest Territory". The northern boundary of Illinois was originally to extend from at or near the southern tip of Lake Michigan. Michael D. Sublett and Frederick H. Walk explain at Location that this involved

the last-minute shift in 1818 of the boundary from its intended location at 41° 44' North to 42° 30' North, a distance of approximately sixty miles. That deviation from the boundary prescribed in the Northwest Ordinance of 1787 increased Illinois' territory by nearly 20 percent, an area roughly equivalent in size to Massachusetts.

Mr. Lindquist says this part of Illinois is sometimes "referred to informally as 'Baja Wisconsin'!" In a lifetime living in southern Wisconsin, I'd never heard that before.

The official state highway map shows the Illinois-Wisconsin boundary angling slightly south of latitude 42° 30' North as it runs west to east. If that's accurate, Sharon and parts of Beloit and Pleasant Prairie are indicated as being in Alta Illinois.