Section 95 of the Constitution Act, 1867

In 1867, Canada's economy was largely agricultural in nature, and new settlers generally came to Canada to farm. Agriculture and immigration were therefore linked together as similar subject matters. Because both subject matters could have wide-ranging effect, they were assigned to both levels of government on a concurrent basis, rather than the exclusivity principle which applies to the lists of federal powers set out in section 91 of the Constitution Act, 1867, and the provincial powers set out in section 92. Section 95 provides that in case of conflict between a federal and provincial law dealing with agriculture or immigration, the federal law prevails, an example of the doctrine of federal paramountcy.^{[8]: 300–301}

The courts have interpreted the agriculture power as applying primarily to the activity of farming. Once agricultural products have left the farm and entered the stream of commerce, they are not subject to regulation under the agriculture power.^{[8]: 301–303}

There has not been a great deal of litigation involving the scope of the federal and provincial immigration powers. The few cases that have been decided gave a broad scope to the federal paramountcy. As well, there were nineteen cases where the federal government disallowed provincial laws relating to immigration.^{[8]: 304–307}

Section 91(25) of the Constitution Act, 1867 gives the federal Parliament exclusive jurisdiction over "Naturalization and Aliens".