Edgewood is the least known of Long Island's state hospitals. This is probably because it had the shortest lifespan and was very close to Pilgrim State Hospital. Edgewood was opened in the early 1940s. It was originally owned by the US Federal Government, who used it for "shell shock" suffers returning from WWII. Along with part of Pilgrim it was then called Mason General Hospital. It is also said that POWs were housed there during the war.
The government commissioned a documentary, Let there be Light, that was filmed at Mason General. This video offers us a rare look at Edgewood while it was an active facility.
Eventually Edgewood was transfered to Pilgrim and used as wards for tubercular and diabetic patients. In 1971 it was shuttered, though everything was left behind.
In 1989 the main building was demolished and in following years the other structures were razed. The land was turned into a preserve. Many reminders of the past in the preserve.