Until the early 20th century, Canada was primarily an agricultural nation. Since then it has become one of the most highly industrialized countries in the world as a direct result of the development of the 'heartland'. To a large extent the manufacturing industries present in the heartland are supplied with raw materials produced by the agricultural, mining, forestry, and fishing sectors of the Canadian economy, a region known as the 'hinterland'. The 'heartland-hinterland' concept in Canada describes patterns of economic power, namely, where economic power and control resides within the nation. Thus, the heartland-hinterland concept distinguishes raw-material and staple-producing hinterlands from the capital service industrial heartland and reveals the metropolis or dominating city of the system. At a national scale, the Canadian metropolis is Toronto, and the region with the most influence is the Great Lakes-St. Lawrence Lowlands. But while immense influence radiates outward from the metropolis located in the heartland, the relationship between hinterland and heartland is one of intimate mutual dependency. In modern Canadian economics, neither region can exist without each other, and the well-being of one directly affects the other. These two regions show remarkable contrasts, yet they are to a large extent interdependent on each other, clearly suggesting that the heartland-hinterland distinction is quite relevant in terms of Canada's economic geography.

Upon discussing the importance of the heartland-hinterland in Canada, it is necessary to discuss what each term refers to. According to McCann the heartland is an area "... which possesses favourable physical qualities and grant food accessibility to markets; they display a diversified profile of secondary, tertiary, and quaternary industries; they are characterized by a highly urbanized and concentrated population which participates in a well-integrated urban system; they are well advanced along the development path and possess the capacity for innovative change." Literally, hinterland means 'the land behind', the area from which a heartland draws its raw materials and which, in turn, serves as a market for the heartland's manufactured goods.

The demographic and economic characteristics of Canada's heartland are that it contains over 50% of the nation's population and 70% of its manufacturing industries in only 14% of the nation's area. Canada's heartland is southern Ontario and Quebec stretching from Quebec City to Windsor. This heartland, occupying the Great Lakes-St. Lawrence Lowlands, coincides with several favourable physical characteristics such as fertile Class 1 and 2 soils in addition to humid continental climate for optimal agricultural conditions. However, the "hinterland regions display harsher or more limiting physical characteristics. The Cordillera, Interior Plains, Canadian Shield, and Appalachian regions yield tremendous resource wealth, but their soils, vegetation, and climatic patterns do not favor wide distributions of population and concentrated development." Canada's heartland is illustrated on the map below.

With the overwhelming presence of the above-mentioned features, this region dominates Canada's economy due to diverse agricultural production as well as its accessibility to the heartland of its major international trade partner, the Untied States, which is focused around New York City. "It is the heartland that creates the demand for staple commodities, supplying the hinterland, in turn, with capital, labour, technology, and entrepreneurship, those factors of production which are so essential for the initial growth and sustained development of the hinterland."

The relationship between the hinterland and heartland is complex. Resources flowing from hinterland areas largely go directly to other countries without passing through the heartland. Yet, it is from the heartland that an economy's organization, financial means, equipment, and technical services arise and are paid for by the sale of the resources. Thus, it can be said the hinterland contributes to the support and development of the heartland. The hinterland also benefits from the interaction of its well-developed internal linkages and a large and concentrated workforce that provides a manufacturing core and specialized services.

Another important aspect of the heartland-hinterland distinction is with respect to regional structure, which involves the interaction of both regions. "Locational forces and even policy decisions of a political nature draw secondary manufacturing and service activities, as well as skilled labour force, to core areas." The concentration of corporate headquarters and financial institutions in the core also causes a flow of profits from the hinterland to the heartland, ultimately causing difficulty