Located at 18 King Street East, the flour and grist mill opened in 1869 by businessmen William Needler and Thomas Sadler. Its continued growth under Needler and Sadler’s ownership made the mill an attractive investment for William and J. D. Flavelle. Upon hearing of Needler’s retirement, William and J. D. Flavelle, along with their uncle and business partner J. R. Dundas bought out Needler’s interest and assumed control of the enterprise in 1884.
Under Flavelle and Dundas’ ownership and J. D. Flavelle’s leadership, many changes occurred that made this mill one of the most competitive in the province. J. D. Flavelle, known for his infectious energy and strong business skills, was chosen to be the mill’s new manager. The Sadler, Dundas & Flavelle Milling Company expanded into the oatmeal, barley and feed business in early 1895, substantially increasing their margins and daily output. Since 1884, the mill had ground 30,000 bushels of Manitoba hard wheat each month while its flour successfully competed with that of large companies such as Montreal’s Ogilvie Milling Co.
The mill underwent more changes in ownership with continued success for the rest of the Flavelles’ tenure. It became the Flavelle Milling Company in 1899, after Sadler retired, J. R. Dundas died, and the Flavelles assumed complete control of the business, its output reached a peak of $1,500,000 per year in 1904. Competing successfully against top flour brands around Canada, the firm was one of thirteen mills acquired in a large merger to be known as Canadian Cereal and Milling Company in 1910. J. D. Flavelle was elected president of the large firm before resigning a year later and selling his stock completely, thus finally retiring, or so he thought at the time.