How did hinsdale IL get its name?

Yes, there is an organization called this. I do not know enough about them to call them a cult but most people around Hinsdale are wary off them and refer to them as such. They have recently sold...

Half is in Du Page County half is in Cook County.

It's named after Illinois State Normal University, now known as Illinois State University, which is located in Normal, Illinois. A Normal school is meant to teach students to become teachers.

Rufus Easton, the founder of Alton, IL and the first postmaster general of the Louisiana Purchase, named it after one of his sons. He also named a number of streets in the city after his children.

It is 23.1 miles according to Google Maps.