Joseph William Hart, the son of Emeline Robertson and the Reverend James R. Hart, a Methodist minister, was born 19 November 1865 at River Philip, Guysboro County, Nova Scotia. He attended Ontario Agricultural College, Guelph, and, following graduation in 1887, studied at the Royal School of Artillery at Kingston, Ontario. On 10 November 1892 he married Minnie Blanche Dykeman (1869-1939) of York County, New Brunswick, and they had four children: Dorothy (Cobb), Charlotte Robertson (Peck), James Gilbert, and William Edward.

During his professional career, J. William Hart changed his place of residence many times. In 1891 he took charge of the Dairy School at Sussex, N.B., relocating in 1893 to South Carolina to become a professor at Clemson College (1893-1898). Over time Hart taught in several other academic settings including the University of Illinois (1903-1905) and the University of Georgia (1911-1914). He also held a number of government or managerial posts, taking charge of the Dairy School at Queens University, Kingston (1898-1903) and the Fazenda Modelo or Experimental College, San Paulo, Brazil (1905-1910). He also worked for the United States Department of Agriculture in both San Juan, Puerto Rico (1910-1911) and at department headquarters in Washington, D.C. (1911).

Despite well-respected credentials, Hart felt compelled to resign his position as professor of dairy husbandry at the Agricultural College of the University of Georgia when pressured to become an American citizen. He accepted the position of assistant superintendent of Jekyl Island, Brunswick, Georgia where he was in charge of large farming, fishing, game, and forestry interests. On 29 May 1914 he was shot and killed on the island by a local fisherman. The shooting was ruled a homicide. Following her husband's death, M. Blanche Hart returned to New Brunswick, settling initially with her mother, Charlotte Dykeman, in Fredericton, and later with sons Gilbert and William in Saint John.

During the Great War, Gilbert Hart served overseas. He saw action at the Somme and Vimy Ridge. Brother William E. Hart attended King's College, Halifax, and was ordained a priest in the Anglican Church. He married Beatrice Euphemia (Willie) Wilson, and they had five children. William Hart served in the parishes of Ludlow and Blissfield (1932-1937) and Norton / Springfield (1937-1978). His mother resided with him for a number of years. She died at the rectory in Lower Norton on 14 November 1939, at age 70. William died on 11 February 1990. His sisters, Dorothy and Charlotte, who were educated both in the United States and at Halifax Ladies College and Havergal Ladies College (Toronto), married in the United States and remained there.