The last major one of these "glacial" time periods came during the Pleistocene Epoch
The 
skeleton came to the Ohio History Connection, on loan from The Ohio ... of these 
advances and retreats in the Midwest is four major glacial advances ... Lake Erie 
is one of Ohio's greatest resources and owes its origin entirely to Pleistocene 
glaciers... [DOC] [TLE] 10(ad) Introduction to Glaciation - Physical Geography [PAR] However, there were periods of times when the Earth's average global 
temperature ... at 800 million years ago when glaciers came within 5 degrees of 
the equator.