Why did industrialization lead to imperialism?
Industrialization is the process by which a society moves from being primarily agricultural to largely based on production and manufacturing. Although industrialization and imperialism tend to overlap and intersect, one does not always lead to the other. In fact, there are many examples of pre-industrial societies invading, occupying, and annexing other territories for reasons other than economics. Nevertheless, over the last two hundred years or so, imperialist policies have frequently been intertwined with industrial ambitions.
In US history, these two aspects of society have had a strong influence on the ways in which the nation was formed. For example, the mechanization of labor in the late 18th and early 19th centuries meant that agricultural and manufacturing output could be increased, giving the nation more economic power and influence in global trade. In order to grow that power and influence, many in positions of authority sought more land and resources in order to expand production. As a result, the US government began to negotiate with the Native peoples that occupied territories in the South, West, and Midwest. When these negotiations stalled or failed, the federal government exerted considerable pressure and force to remove the Native inhabitants and take over the land for settlement and expanded production.
In the case of the US, the power acquired from industrialization led to a need and or desire for more land to increase agricultural and manufacturing productivity. In order to gain access to that land and its resources, the government exerted force on the people that lived there and eventually drove them out in order to grow their empire.