In 1898, Mannix started a contracting business and by the end of his life had built it into one of the largest construction firms in western Canada.

George fought with the Canadian Militia in both the Fenian raids and the Red River Rebellion, and then began homesteading in Manitoba.

On her father's side, Bunn's great grandfather was the Hudson's Bay Company fur trader William Sinclair (1794–1868).

On her mother's side Bunn was descended from HBC officials Robert Campbell (1808–1894) and William McGillivray (1764–1825).

Mannix and Bunn had three children together in addition to Frederick: William Alfred Victor (1875–1960), Leonard Nial (1887–1959), and Frances Alicia (1891–1976).

[2] In 1905 Mannix moved to Edmonton and took night courses to improve his education, while continuing to build his business.

Over the next several years Frederick C. continued to amass wealth and in 1951, shortly before his father's death, he repurchased the company from the Americans.