The importance of Bellamy's Flour Mill lies in the economic impact of such mills on rural Upper Canada and the effect of steam power in industrial development.

In 1821, the principal agricultural crop in the province was wheat. For the wheat to become useful it had to be ground into flour, and so mills were required. When Samuel Bellamy constructed his mill in Augusta Township, there was an immediate demand for his services. His business was custom work. He received grain from his farming neighbours, milled it to their specifications and returned it to them. As payment for his work he kept 1/12th of the wheat ground. This toll was established by law, so the miller could make a living, but not charge exorbitant prices.

The relationship between farmer and miller was very important; the farmer expected quick service, to be able to supervise the exact grade of flour he wanted, and a good return on his wheat. Like the village store, the flour mill provided a meeting place for farmers and tradespeople. Activity at the mill provided business opportunities for other entrepreneurs, hotel owners and storekeepers, tradesmen and professionals

Before 1863, the mill operated solely by water power. Water turned large stones, which ground the wheat into different grades of flour. Because the supply of water was limited, this meant the mill only ran efficiently for about four months of the year. The community need for water in summer, and cold in winter made it difficult to use the water supply for grinding all year. In 1863 a fire destroyed the interior of the mill. Three months later, it was back in operation, with new steam-powered machinery. Additional stones were also purchased. This meant that the mill could produce more flour at a time, and more importantly, could now operate all year.

On its new site in Upper Canada Village, Bellamy's Mill represents the focal point of a village and demonstrated the importance of the milling industry.