Approximately how many years ago did the Great Lakes begin to form in the upper east US region?

One of my favorite things to do in late summer/early fall living in SE MI is head to a park we call Metro Beach where a hwy called 16 mile (aka metro Pkwy) ends & walk to the edge of the shoreline that juts out to the lake's edge,relaxing on a park bench listening to the waves gently splash & gulls caw. Where a canal that separates the park and well to-do residences in Harrison Twp. that serves as a portal for yachts & such going out/in from the lake. I enjoy reading the names the owners give their crafts as some on the boats will sometimes wave to the kiddies that often gather at the park. Very therapeutic.

America the Beautiful! ❤️

we would be lost and financially insecure, without those lakes!!