After his exploration of the northern Mississippi valley and western Great Lakes region, he published an account of his expedition, Travels through America in the Years 1766, 1767, and 1768 (1778), that was widely read and raised interest in the territory.

Around 1748, Carver moved his young family to Montague, Massachusetts, at the time a small frontier settlement, where he served as a selectman.

Following his death, some of his heirs claimed that he had obtained a land grant from two Sioux chiefs for a large area of eastern Wisconsin during his expedition.

Carver recorded visiting a small Métis settlement at the foot of Green Bay (Lake Michigan), as well as a French monastery nearby in Des Peres, Wisconsin.

Carver crossed to the Wisconsin River and then traveled down the Mississippi, emerging at the great trade encampment at Prairie du Chien.

He spent some time with the tribe near the falls but turned south, down the Mississippi, to find a more suitable place to spend the winter.

During this portion of the trip he came upon a site sacred to the Dakota people, Waḳaŋ Ṭípi, which European-Americans have subsequently called Carver's Cave.

Carver learned that his sponsor, Royal Governor Robert Rogers, was under suspicion of plotting treason against England.

Carver submitted a list of expenses to his superiors, but payment was denied on the grounds that Rogers had not had sufficient authority to order such an expedition.

In 1769 Carver left for England to petition the government for his promised payment and to claim the reward for identifying a potential Northwest Passage.

He ultimately received two separate grants from the Crown to cover his expenses, although not the great reward for identifying a Northwest Passage.

More recent research suggests that, while Carver carried out the tour he describes, he suppressed the fact that he performed it as a hired agent of Royal Governor Major Robert Rogers, rather than on his own responsibility.

[8] Lettsom claimed he had in his possession a deed, signed by two chiefs of the Sioux, giving Carver title to about 10,000 square miles (30,000 km2) in what is now Wisconsin and Minnesota.

: from the Falls of St. Anthony, running on the east bank of the Mississippi, nearly southeast, as far as Lake Pepin, where the Chippewa joins the Mississippi, and from thence eastward, five days travel, accounting twenty English miles per day, and from thence again to the Falls of St. Anthony, on a direct straight line.In other words, this triangular tract in northwestern Wisconsin and eastern Minnesota would have been bounded by lines running from modern Minneapolis southeast to Pepin, then due east to near Stevens Point, and from there northwest roughly through Eau Claire to Minneapolis.

Congress investigated their claim and ultimately concluded that English law at the time prohibited any land grants to individuals.

In 1817, Sioux elders in St. Paul, Minnesota, had told Carver's heirs that no chiefs ever existed by the names on the deed.

Land speculators and con-men continued to promote the sale of portions of "Carver's Grant" for another half century.

According to the Wisconsin Historical Society: Modern scholars who have reviewed all the evidence cannot confirm the existence of any such grant to Carver, who never mentioned it in surviving records.

They have, however, documented a great deal of deceit, manipulation, and self-delusion by his heirs and their agents as they attempted to sell portions of the land in the decades following his death.

[10][11] A 2005 episode of the Discovery Channel series A Haunting claimed that the ghost of Carver upset residents of Summerwind.