Thacher Island was sighted by Samuel de Champlain in 1605, by Captain John Smith in 1614, and likely many others before them.

The name comes from a shipwreck described as "pathetic" by historians. A small boat out of Ipswich, bound for Marblehead, was caught in the Great Storm of August, 1635, and was dashed to pieces on the rocks of the Island. Of the 23 passengers and crew, only Anthony Thacher and his wife, Elizabeth (Jones) Thacher, survived, watching helplessly as their children and friends were swept away.

On September 3, 1635, the General Court awarded Thacher 40 marks, and in 1636-37 the General Court voted to grant Thacher the Island "at the head of Cape Ann, as his inheritance."

In 1717 the near 50-acre Island was sold by John Appleton, an heir of Thacher, of Ipswich to the Reverend John White for 100 pounds.

In 1726-27 the Reverend John White sold Thacher to Joseph Allen for 175 pounds. Joseph Allen, Jr. then owned it until his death in 1750.

In 1771, the Colonial Government bought it back for 500 pounds. The same year, the twin lighthouses were erected and lighted for the first time on December 21st.

The present 123-foot granite towers were completed in 1861, raising the lights to 166 feet above sea level. In 1888 the Town of Rockport adopted the Seal of the Island as its official seal.

Early in the 1900s, four families lived on the Island to run the lighthouses and fog whistles. Descendants of these families still live in Rockport.

The north light was shut off in 1932, as an economy measure. The Coast Guard, which had manned the Island for many years, removed its last crew of four men in 1980. At that time, the south light and the fog whistle had become automated, and the Town of Rockport took over the Island by lease from the U. S. Coast Guard.

In 1983, the Thacher Island Association was formed as a nonprofit organization to support and encourage historic preservation and restoration of the structures on the Island. The Association financed the design and construction of a custom made aluminum launch, a mini landing craft, to provide access to the Island.

Major restoration work was completed in 1988 on the once abandoned North Tower, and it was relit and approved as a private aid to navigation. A 15-watt fluorescent lamp replicates the amber light of the original oil lamp and can be seen for almost eight miles.

In the summer of 1998 the Coast Guard installed a solar panel to power the south tower and fog horn.

The entire Island and its structures were designated as a National Historic Landmark by the National Park Service. This designation in January of 2001 officially recognizes Cape Ann Light Station’s significant impact in our nation’s maritime history.

A total restoration of the brick two story duplex assistant keepers quarters and a guest apartment on the Island took place during the summer of 2002 allowing the Town to begin renting the guest apartment and providing an income stream to be used for further restoration. The Association maintains volunteer keepers on the Island during the summer months to assist and inform visitors, and to provide the daily upkeep needed for a ship-shape facility.

Also in 2002 the southern 28 acres of the Island and its structures were deeded over to the Town of Rockport by the U.S. Coast Guard. The north end and tower is owned by the U.S. Fish & Wildlife Service and managed by the Town on their behalf as a wildlife refuge.

Ongoing work includes restoration of the island and its structures to their original 1800’s condition and keeping it open to the public as a historic and educational facility.