It was probably first seen by Europeans in 1614 when Adriaen Block, a Dutchman employed by the Dutch West India Company, charted the area.

The light marks the east side of "Plum Gut", a mile-wide entrance to Long Island Sound with extremely strong tidal currents.

[8] After passing through the possession of more than 20 families, in 1899, the island was purchased in its entirety by the United States government following the Spanish–American War for approximately $90,000.

In 1954, the United States Department of Agriculture (USDA) established the Plum Island Animal Disease Center (PIADC).

The USDA continues its long running science mission at PIADC jointly with DHS, who are charged with the safe and secure operation of the facility.

In January 2009, the United States Department of Homeland Security (DHS) selected the City of Manhattan, Kansas, as the site for the NBAF, and decided to relocate the PIADC there as well.

[10] However, the decline in real estate values stemming from the subprime mortgage crisis and late-2000s recession caused the sale of the island to be considered no longer viable.

A regional environmental group, Save the Sound, led the legal aspects of the movement to preserve Plum Island[13] including the repeal of H.R.

Congressman Tim Bishop (First Congressional District of New York) introduced a new bipartisan bill ('Save, Don't Sell Plum Island').

On August 29, 2013, the USDA and DHS announced a final Record of Decision (ROD) which determined that the entirety of Plum Island was to be sold to the private sector to help offset the cost of constructing the replacement facility.

On September 30, 2013, New York Governor Andrew M. Cuomo sent a letter to the United States Department of Homeland Security (DHS), and United States General Services Administration (GSA), calling for both agencies to submit to a consent order requiring them to present a comprehensive environmental cleanup plan for Plum Island, in Suffolk County, New York, and giving New York State final review of the Island's conditions before it would be put up for sale.

of Homeland Security (DHS) and U.S. General Services Administration (GSA), indicating a 60-Day "Notice of Intent to Sue" these agencies.

Under the bill, the Department of Homeland Security must offer the island for transfer to other federal agencies such as the Fish and Wildlife Service.

The provision was based on legislation first introduced in 2015 by Representative Lee Zeldin, whose district includes Plum Island.