I checked out a chart from about 1853. There were two inlets at Fire Island. One was Oak Island Inlet, west of Captree Island. There was also an inlet at Gilgo Beach. On this chart, there is no inlet at Zachs Bay. I think that broke through later. Jones Inlet was known as "New Inlet". I will try to find the link to this chart. Real interesting to look at. I will post if I can find it.