Yet, it was golf that drove her. Through the 1920s, she was the female darling on the links in Canada. Along the way, Mackenzie captured four Canadian Open amateur championships and six Canadian Closed amateur crowns. She won the Canadian senior women’s association title eight times, the Ontario crown nine times, the Ontario senior title twice and the Toronto tournament 10 times.
Mackenzie also participated abroad in the U.S. and Europe and won a multitude of tournaments throughout the province and at private clubs. She was invited to join the Scottish national team participating in the British Ladies' Open in 1929 and that was one of her fondest memories.Mackenzie’s career spanned more than 50 years, her last victory coming at the Ontario senior championships in 1969 when she was a young 78.
When she wasn't on the course, she spent a few years as sports instructor at Havergal College and from 1914-30, she was employed by what was then known as the Canadian Bank of Commerce. She also operated a sports-clothing boutique from 1930-59.
But her biggest project was this: she single-handedly founded the Ladies' Golf Club of Toronto in 1924, as an inspiration to budding young girls and women wanting to play the game and there was another reason. "Ada started the club because she had no place to play,’’ said Susan Lockwood, chair of the archives committee at the Ladies’ Golf Club. "There was an American woman from Long Island in the same boat as Ada so they both decided to build their own club."
Men were allowed to play at the Ladies’ club but special hours and weekends were devoted to women. This undertaking didn’t come without some financial ingenuity. She came up with the necessary $30,000, which she raised through the issuance of shares she sold in person. Eighty years later this year, that club thrives as the only golf club in North America reserved for women.