17th century
In 1604 French explorers arrived on the island. Shoodic River was now called Sainte Croix River because of its cross-shaped stream. The island lost its entire Passamaquoddy name and was called by the French Sainte Croix Island. On the Island, the French settlers got the land ready for cultivation and removed stones and trees which were obstacle to the construction of dwellings. They sowed gardens, dug a well and built a windmill. Nineteen buildings built in wood formed the Sainte Croix Island settlement.

After building their homes, the French explored Sainte Croix River, its estuary and the coast. Samuel de Champlain drew a map of the Quoddy region and named a few places. Native people and French settlers had peaceful relations. The French even traded objects with Native people to get fur.

In October 1604, the whole island was covered in snow. The French settlers were ill-prepared for this early winter and its bitter cold; only half the colony survived the freezing winter, scurvy and starvation. In spring 1605, Sainte Croix Island colony was abandoned: the French settled in Port-Royal.

The island was still visited by the French even though they lived in Port-Royal. Champlain and Poutrincourt stopped there in 1606 while they were exploring Sainte Croix River shores. A year later, Lescarbot visited it and wrote in his book that some dwelling were still in good shape. Captain Platrier also stayed on the Island during the winter of 1611-1612. Unfortunately, in 1613, Sainte Croix Island settlement was totally destroyed by Samuel Argall. After this invasion, there is no record of people living on the island or visiting it.

In 1632, the name "Sainte Croix Island" disappeared from any maps or register books.

18th century
During this century, the island was known as the Dochet Island. This new name came from Theodosia, a little girl who apparently visited the island quite often. Other people called the island, during the 1770s, Bone Island, referring to all the bones coming from the cemetery.

After the War of Independence, Sainte Croix Island was an important element to determine the boarder between the United States of America and the English colonies of North America. In 1783, the conflict was resolved by the signature of the Treaty of Paris: the island was chosen as a reference point for the new international boarder.

Another problem between USA and England had to be solved. A commission was mandated to identify the real Sainte Croix River. In 1797, Robert Pagan and Thomas Wright succeeded in finding the Sainte Croix Island by following the indications left by Samuel de Champlain: the Docea's Island was in fact the Sainte Croix Island where the French attempted to establish the first European settlement in America.

19th century
Better known as the Dochet Island, the island also had many other different names: Neutral Island (1810), Big Island (1820), Bone Island (1830) and Demonts Island (1860-1870). On a map of Maine, it was identified by its Passamaquoddy name, Mottoneguis.

Throughout this century, many individuals inhabited the island. First, in the early 1800, John Hiliker and his wife lived on the island even if they were not the owners. No dwelling had been constructed during this time and, according to the legend, both spouses were buried on the island.

During the War of 1812, trade between the United States and England was prohibited, and the island became a very good place for smuggling. During the 1820s, John Brewer bought the island and the Hilikers lived there as Mr. Brewer's tenants. In 1826, John Brewer sold the island to his brother. Although Stephen Brewer never lived on the island, he constructed a farm, a house, a barn, outbuildings, and a wharf.

From 1830 and 1855, different people lived on Sainte Croix Island. First, there was the Mingos who planted gardens and orchards. Then an individual named Treat lived on the island for a short period of time and was quickly replace by Mr. Chase and Mr. Thompson. Those gentlemen destroyed the farm and its building to have wood during the cold winter. They stayed on Sainte Croix Island till the construction of the lighthouse in 1857. The American government decided to buy the island from Stephen Brewer's heirs and built a light station (lighthouse, house and small outbuildings). The government sold the southern part of the island to four different families who lived there until they sold back the island in 1967.

From the mid-1800 to 1865, a company exploited a sand quarry on the Sainte Croix Island. Archaeological finds were made while the quarry was in operation; including the excavation of five small cannonballs from the 1604 settlements by quarry company employees.

20th century
On June 25, 1904, three magnificent ships from France, United States and Canada were anchored near by the Sainte Croix Island to celebrate the 300th anniversary of the first European settlement in America. A commemorative plaque was placed on a boulder near the north end of the island.

Then on June 8, 1949, the American Congress designated the Sainte Croix Island as a national monument, recognizing at the same time the historical significance and importance of the region. A few years later, in 1967, the National Park Service bought the island from the US Coast Guard and different small owners. Furthermore, in September 1984, the Sainte Croix Island was designated as an international historical site by Congress in order to preserve a part of American and Canadian heritage.

Finally in 1976, a fire totally destroyed the lighthouse and other buildings. Only the boathouse (1885) and the brick house (1906) remained intact on the Sainte Croix Island.