In its earliest years of human occupation, Ministers Island was an important summer camp for the Passamaquoddy First Nations. Archaeological evidence indicates that the Passamaquoddy inhabited this island after the retreat of the glaciers 13,000 years ago. Qonasqamkuk, now known as St. Andrews, was an important meeting place & sacred ceremonies by the Passamaquoddy were held there.
The first known European settlers on the island were John Hanson and his family, from 1778-1784. At the time, Ministers Island was referred to as Chamcook Island, in the Province of Nova Scotia. The island was later granted to Captain Osborn by King George III for services rendered during the American War of Independence. Sometime between 1788 and 1791 the Rector of St. Andrews, Reverend Samuel Andrews formerly from Wallingford, Connecticut acquired ownership of the island from Captain Osborn. Andrews paid 250 pounds for the Island. This sale wasn't without some controversy as the earlier loyalist settlers of the island, claimed that they had forfeited ownership as a result of some trickery and intimidation.
At some point between 1788 and 1791 Reverend Andrews built the small stone cottage on the Island that is still there today. Thereafter it acquired its informal designation as Ministers Island. The Rector is remembered to have laboured by horse and buggy along treacherous winter roads and trails to visit parishioners in the outlying areas. With the tide covering the bar a large part of the day, getting on and off the Island, and even coming into town for regular church service, would not have been the easiest task. Perhaps for this reason Andrews spent about half his time on the mainland.
Except for a brief interlude between 1798 and 1841, Ministers Island remained entirely in the Andrews family until 1891, when a part of it was sold by Edwin Andrews, great grandson of Reverend Andrews, to Sir William Cornelius Van Horne.
Van Horne purchased part of the island in 1890. He continued to buy other parcels with the last piece being purchased by his daughter Addie after Sir William's death in 1915. He constructed a summer estate on the site which included Covenhoven - a 50-room summer home with walls constructed from sandstone cut from the shore, a windmill, leading edge gas plant, carriage house, garage, circular bath house and farm buildings. The centrepiece of the agricultural buildings is the livestock barn, a massive two-story timber structure with a hipped gable roof, which was home to Van Horne's thoroughbred horses and prized herd of Dutch belted cattle.
In its day, the Island and Van Horne's activities were a major tourist draw for St Andrews and played a major role in the economic development and support of the region. Indeed he was single-handedly responsible for attracting many of his wealthy friends who came and made St Andrews their summer homes and established St Andrews as Canada's first and oldest seaside resort. Van Horne's engagement of Edward Maxwell, the renowned Boston and Montreal Architect in the creation and design of Covenhoven and the large agricultural barn set the stage for Maxwell's shaping of many of the magnificent buildings in St Andrews. Following Sir William Van Horne's death in 1915, his daughter Adaline inherited the property and maintained it until her death in 1941. Afterward, it was placed in a Royal Trust and maintained by Edith Bruce, the wife of Adaline's brother Richard Benedict Van Horne, and his granddaughter Beverley Ann. When Beverley Ann came of age in 1953 she inherited the island, but showed little interest in maintaining it, and the island was eventually sold out of the Van Horne family.
In 1958 the Historic Sites and Monuments Board of Canada rejected Covenhoven as an historic site and the island was put up for sale. It was listed for $80,000 including 500 acres, all of the buildings and a working farm producing 200 tons of hay and enough oats to feed 100 head of cattle. In 1960, after a failed last-ditch attempt by locals to keep the island from falling into American hands ,it was sold to an Ohio syndicate that planned to turn it into a semi-private club for shareholders and their friends and acquaintances.
In 1967 after numerous financial problems, the island, its buildings and all of the treasures housed therein, was sold again to real estate developer, Norman Langdon a resident of Maine. This was after, yet again, an attempt to have the provincial government recognize the island's potential as a park development in conjunction with an historical complex. Langdon envisioned a significant cottage development on the island and proceeded to sub-divide the land. Langdon sold three lots to other parties. He invested over $300,000 in renovations. Numerous buildings on the site were removed and poor quality repair work on other buildings left them in poor condition.
In 1977 it was announced that the island and all the furnishings would be put up for auction. Local activists attempted to halt the proceedings and lobbied the Provincial government who had been in talks with Langdon to buy the property to step in. In March the Province declared Ministers Island a provincially protected site. In August the deal was finally done at a cost of $855,000 for a nearly empty property that could have been purchased completely intact in 1971 for $400,000.
In 1978 Parks Canada National Historic Sites and Monuments Board recognized the island's Shell Midden noting the importance of the site to First Nations history
The island was locked and access was denied to visitors until 1983 when limited tours were allowed.
Since that time numerous concepts have been floated for the island; everything from a working organic farm; time-share condos; railway museum to an international centre demonstrating wind, solar and tidal power.
In 1996 Parks Canada National Historic Sites and Monuments Board designated the island a National Historic Site.
In 2008 the provincial government of New Brunswick signed a long-term lease with the current operators The Van Horne Estate on Ministers Island Inc. (VHEMI) which is a volunteer, not-for-profit charitable body representing the local communities who believe strongly in the provincial and national importance of the Island.