There are two main ways in which the Industrial Revolution and imperialism were linked to one another. First, the Industrial Revolution made imperialism more necessary. Second, it made imperialism more possible.
The Industrial Revolution helped to create a situation in which the European countries (as well as the United States and, eventually, Japan) felt that they needed to have large empires. They needed these empires for two main reasons. First, they needed places from which to get raw materials. The industrialized economies of these countries needed raw materials and imperialism was seen as a way to get those materials. Second, they felt they needed captive markets in which to sell the goods produced in the factories. Imperial possessions could be useful in this way too.
The Industrial Revolution also made it much more possible for these countries to take and hold empires. The Industrial Revolution greatly increased the military strength of these powers. It gave them better weapons. It gave them ships that could reach various parts of the world faster and more reliably than sailing ships could in pre-industrial times. These sorts of factors made it easier for Europeans to reach and conquer every corner of the globe.
In these ways, the Industrial Revolution and imperialism were closely connected to one another.
According to Western powers, imperialism was necessary for the industrial revolution because of the increased need for raw materials and market expansion. The countries needed to expand their territories in order to increase the resources available for the industries. The empires expanded into far-flung regions in Asia and Africa. The raw materials required by the imperialist countries included cotton, coal, and iron ore. Cheap labor provided by natives in the conquered territories was also used to extract the raw materials, which were transported to the industries.
Mass production techniques during the industrial revolution increased the need for new markets. Industries were competing for higher profits, and the governments supported their ventures due to the taxes remitted by the industries. Thus, the expansion of the country’s territory resulted in the direct expansion of their market and a subsequent increase in industrial profits and government revenues.