FACTORS 



45 



The History of the Chicago Region 



Fig. i. — Showing the region of the Great Lakes when the Wisconsin ice sheet 

 was retreating from its maximum extent (after Atwood and Goldthwait). 



Fig. 2. — A part of the same area, showing the drainage of the ice sheet by the 

 Kankakee and Huron rivers through Dowagiac Lake (from Lane after Leverett). 



Fig. 3. — Showing a later stage of the retreat of the ice sheet — the Glenwood 

 stage (from Lane after Leverett). 



Fig. 4. — A later stage of the same — the Calumet stage of Lake Chicago (from 

 Goldthwait after Leverett and Taylor). 



Fig. 5. — A still later stage— probably the Tolleston stage (from Lane after 

 Leverett) . 



Fig. 6.— A post-Tolleston stage (from Goldthwait and Atwood after Leverett 

 and Taylor) . 



