I think it was 1.5 miles of ice deep, but I’m too old to remember..
When I was in college, my geology professor discussed glaciation and that there was a series of small hills just a few miles north of the college that he had been curious about when he first moved here in the flat lands of northwestern Indiana. I got permission to visit the hilly area from the farmers who owned it and proceeded with his examination. He concluded that the hills were actually a glacial moraine formed by a pause in the retreating glaciers that covered and leveled all of northern Indiana and Illinois.