Papers : 1792-1817.

William Jarvis was a son of Samuel Jarvis and Martha Seymour of Stamford, Connecticut. He married Hannah Owen Peters, the daughter of the distinguished Loyalist clergyman, Rev. Samuel Peters, who had fled to London, England, from Hebron, Connecticut, after suffering severe persecution at the hands of the rebels because of his loyalty to the British cause. In 1777, William Jarvis joined the Queen's Rangers, which was commanded by Lt.Col. John Graves Simcoe, and in 1782 received his commission as a coronet. At the end of the American Revolution he received an officer's half pay and returned to Connecticut where he and other Loyalists were treated with such hostility that he left for England. In 1785, Simcoe recommended him to Henry Dundas, the Home Secretary, for the position of provincial secretary of the new province of Upper Canada. He arrived in Upper Canada in 1792 with Simcoe, who had been appointed the first lieutenant governor of the colony, and lived at Newark (Niagara-on-the-Lake) until the seat of government moved to York (Toronto) in 1798. While still in England, Jarvis was named the first grand master of the newly organized Masonic Lodge of Upper Canada. In 1794 he was appointed deputy lieutenant of York County. He was also a justice of the peace for the Home District and a colonel of the Lincoln militia. 

William Jarvis belonged to the colony's early official families who formed a tiny governing elite, and he, like others of his group, sought to advance his children in society. His son, Samuel Peters Jarvis, became deputy provincial secretary, and later chief superintendent of Indian Affairs, 1837-1845. He married Mary Powell, a daughter of Chief Justice William Dummer Powell. Two of his daughters married sons of Robert Hamilton, the wealthy Queenston merchant and sheriff of the Niagara District, and a third daughter married William Benjamin Robinson. Munson Jarvis (1742-1825), a merchant and prominent citizen of Saint John, New Brunswick, was an older brother. A second brother and two sisters were also Loyalists, including John Jarvis, who settled in Kingston, New Brunswick, a sister, Polly Jarvis, who married Fyler Dibblee and also lived in New Brunswick, and Martha (Jarvis) King, who resided in Halifax, Nova Scotia.