when did it happen?
From approximately 75,000 to 11,000 years ago
Wisconsin glaciation
n. The Wisconsin glaciation extended from approximately 75,000 to 11,000 years ago, between the Sangamonian Stage (known globally as the Eemian stage) and the current interglacial, the Holocene. 
when did immigrants stop coming to ellis island UNANSWERABLE where is this island located? New York Harbor can you mention any geographical features of the islands? Ellis Island is in Upper New York Bay, east of Liberty State Park and north of Liberty Island. While most of the island is in Jersey City, New Jersey, a small section is an exclave of New York City. are there any military facilities? Ellis Island was also used by the military for almost 80 years. By the mid-1790s, as a result of the United States' increased military tensions with Britain and France, a U.S. congressional committee drew a map of possible locations for the First System of fortifications to protect major American urban centers such as New York Harbor. what was the state of this place before colonialization? The present-day Ellis Island was created by retreating glaciers at the end of the Wisconsin glaciation about 15,000 years ago. The island was described as a "hummock along a plain fronting the west side of the Hudson River estuary. what is this glaciation process that you just mentioned? It refers to the most recent glacial period of the North American ice sheet complex. This advance included the Cordilleran Ice Sheet, which nucleated in the northern North American Cordillera
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Wisconsin glaciation [SEP] Introduction
During much of the glaciation, sea level was low enough to permit land animals, including humans, to occupy Beringia (the Bering Land Bridge) and move between North America and Siberia. As the glaciers retreated, glacial lakes were breached in great floods of water such as the Kankakee Torrent, which reshaped the landscape south of modern Chicago as far as the Ohio and Mississippi Rivers.