Linked from
The 22 pages that link to Laurentide Ice Sheet, each with the reason it gives.
Great LakesRelated: Its advance and retreat carved and reshaped the basins holding the lakes.
MoraineRelated: Its retreat left extensive moraine ridges across the continent.
Lake AgassizRelated: Its retreat exposed the basin, while its ice blocked northward drainage.
Isostatic depressionRelated: Its weight depressed the crust across a broad area of North America.