The present day footprint of the island is 27.5 acres (11.1 ha) as opposed to the original 3.3-acre (1.3 ha) island.
Though the current island's landmass was originally three separate islands, the Ellis Island Immigrant Hospital consisted of 22 buildings spread over the southern two islands.
The islands were man-made, using excavated fill and concrete from the New York City Subway, as well as other building demolition spoils.
The fill was retained with a system of wood piles and cribbing, and later encased with more than 7,700 linear feet of concrete and granite sea wall, placed atop either wood piles, cribbing, or submerged bags of concrete.
Island 2 was created in 1899, and island 3 in 1906.
The second ferry basin between islands 2 and 3 was infilled in the 1920s to create the great lawn.
It was started by building the concrete and granite seawall to connect the tip of islands 2 and 3.
The basin was subsequently filled to create the lawn.

A central corridor runs southward from the ferry building on the west side of the island.
Two additional corridors split eastward down the centers of islands 2 and 3.

During its peak years, the hospital employed over 150 doctors, nurses, and other staff, many of whom lived in dormitories on the islands.
According to the 1920 Census, 124 lived on the Islands.
Red Cross workers also volunteered frequently, with a special focus on making the hospital more comfortable and enjoyable for the immigrant children.
A hospital school taught children about personal hygiene, neatness, and good manners.
The present day footprint of the island is 27.5 acres (11.1 ha) as opposed to the original 3.3-acre (1.3 ha) island. Though the current island's landmass was originally three separate islands, the Ellis Island Immigrant Hospital consisted of 22 buildings spread over the southern two islands. The islands were man-made, using excavated fill and concrete from the New York City Subway, as well as other building demolition spoils. The fill was retained with a system of wood piles and cribbing, and later encased with more than 7,700 linear feet of concrete and granite sea wall, placed atop either wood piles, cribbing, or submerged bags of concrete. Island 2 was created in 1899, and island 3 in 1906. The second ferry basin between islands 2 and 3 was infilled in the 1920s to create the great lawn. It was started by building the concrete and granite seawall to connect the tip of islands 2 and 3. The basin was subsequently filled to create the lawn.
A central corridor runs southward from the ferry building on the west side of the island. Two additional corridors split eastward down the centers of islands 2 and 3.
During its peak years, the hospital employed over 150 doctors, nurses, and other staff, many of whom lived in dormitories on the islands. According to the 1920 Census, 124 lived on the Islands. Red Cross workers also volunteered frequently, with a special focus on making the hospital more comfortable and enjoyable for the immigrant children. A hospital school taught children about personal hygiene, neatness, and good manners.
Ellis Island Immigrant Hospital