[1]: 9  The island was the site of an early attempt at French colonization by Pierre Dugua, Sieur de Mons in 1604.

In 1984 it was designated by the United States Congress as Saint Croix Island International Historic Site.

[1]: 14 [5] The French noble Pierre Dugua, Sieur de Mons, established a settlement on Saint Croix Island in June 1604 under the authority of Henry IV, King of France.

Earlier attempts at Charlesbourg-Royal in 1541 by Jacques Cartier, at Sable Island in 1598 by Marquis de La Roche-Mesgouez, and at Tadoussac, Quebec, in 1600 by François Gravé Du Pont, had failed.

[6] Cartographer Samuel de Champlain was part of the Dugua expedition and settlement on the small river island in 1604.

[7] The following spring, Champlain and François Gravé Du Pont moved the settlement to a new location on the southern shore of the Bay of Fundy.

[11] During a boundary dispute between Britain and the U.S. in 1797, the island was deemed to be under U.S. sovereignty by a survey of the river which determined it to be on the western side of its main channel.

Canada issued a nationally circulating twenty-five cent piece in 2004 that commemorated the island and the beginnings of Acadia there.

It was given its current International Historic Site designation by Congress on September 25, 1984, unique in the national park systems of both the United States and Canada.