The National Policy was a Canadian economic program introduced by John A. Macdonald's Conservatives in 1879 after they returned to power, however, it was an official policy since 1876. It was based upon high tariffs to protect of the manufacturing industry.

Macdonald campaigned on the policy in the 1878 election and handily beat the Liberals, who were believers in free trade.

The causes of the National Policy are numerous. Macdonald hoped that by creating a strong manufacturing base in Canada the nation would become far more secure and less reliant on the United States. He was also closely linked to the Montreal and Toronto business interests that would benefit from such a policy, and they did play an important role in keeping the Tories in office until 1896.

A protectionist policy was not the first choice of Canadian manufacturers. The ideal for them would have been a unified North American market where they could freely compete with American manufacturers. Despite a brief experiment with free trade in the Canadian-American Reciprocity Treaty before Confederation the Americans were intent on pursuing a strongly protectionist policy, with tariffs far higher than Canada even had under the national policy.

With such high American tariffs Canadian firms could not compete in the United States, but American firms could enter Canada. Especially problematic was the problem of dumping surplus goods at below cost on the Canadian market, so as not to lower prices in the United States.

The policy was introduced in the budget on March 14, 1879, and it created high tariffs on the import of most manufacturing goods. At the same time the tariffs on raw materials were lowered to also help manufacturers. The tariff was not as high as that in the United States, however. The Canadian government was dependent upon revenue from customs and too high a tariff would have cut off almost all imports, thus depriving the government of revenue.

The policy quickly became one of the most central aspects of Canadian politics and it played an important role in keeping the Tories in power until 1896, when Wilfrid Laurier and the Liberals campaigned on a promise to keep the National Policy in place. While many Liberals still supported free trade, the National Policy was too popular in Ontario and Quebec to do away with. When in the 1911 election the Liberals campaigned on free trade they lost the election.

While the policy was popular in central Canada, in the west it was extremely unpopular. The policy forced farmers to buy Canadian agricultural equipment at far higher prices, but they also had to compete on the international market for grain. This opposition to the National Policy played an important role in the rise of the Progressive Party of Canada in the 1920s. Their platform was entitled the New National Policy and it advocated free trade.

The National Policy was slowly dismantled under the many years of Liberal rule under William Lyon Mackenzie King and Louis St. Laurent. At the same time the United States was lowering its tariffs. Complete free trade was not achieved until 1988 with the Canadian-American Free Trade Agreement brought in by Brian Mulroney's government.

The assessment of the National Policy is mixed. In general economists see it as a bad thing that increased prices and lowered Canada's standard of living for many years. They also see it as creating an inefficient economy that had too many monopolistic firms. Historians, however, tend to see it in a more positive light viewing it as a necessary expense to create a unified nation with its own manufacturing base. They also see the policy as increasing Canada's population and encouraging the development of cities and urbanization.

The years right after the policy was introduced saw Canada experience the same type of economic boom that many other nations experienced, as well as the construction of a manufacturing base and the development of the nation, which is generally what the Tories and economic nationalists use to justify the policy.