His grandparents on both sides of his family came to Canada from Eastern Europe, the Leonoffs from Nicolaiov, Russia and the Brotmans from the Polish town Bialykammin in Galicia.

During his second year of classes at the University of Manitoba, he joined the Canadian Armed Forces and was stationed in Kingston, Ontario in the Signal Corps.

[3] Wanting to know more about this history, and realizing that there was no documentation of it, Leonoff began interviewing the Barish brothers and other alumni of the Jewish farm settlements throughout the Canadian prairies.

The Historical Society's oral history program expanded rapidly with the involvement of new volunteers drawn largely from the ranks of the National Council of Jewish Women.

These interviews led to Leonoff's next book, Pioneers, Pedlars, and Prayershawls: The Jewish Communities in British Columbia and the Yukon, published in 1978.

In an effort to reduce the cost of maintaining the site, the committee responsible proposed laying the gravestones flat to allow a motorized lawnmower to pass through more easily.

"[5] Leonoff and his colleague Julius Shore were invited to a site visit with the Cemetery Board and Mountain View staff, with the result that the headstones remained untouched.

[6] For the ensuing 45 years, Leonoff remained actively involved in the work of the Jewish Historical Society, writing frequent articles and acquiring new material for the archives.

Together, these collections number over 300,000 items documenting vast portions of the history of BC, including the logging trade in the early 20th century and the post-war construction of Vancouver.

Leonoff won additional accolades for his other writings, notably the Margaret McWilliams Medal[8] of the Manitoba Historical Society for his 1985 essay, "The Jewish Farmers of Western Canada".