Final answer:
Great Britain's main concern in establishing colonies was to gain economic benefits, primarily through mercantilism and trade laws like the Navigation Acts.
Step-by-step explanation:
In establishing colonies, Great Britain was most concerned with gaining economic benefits. This is evident through the British focus on mercantilism, wherein colonies served as sources of raw materials and markets for British manufactured goods. The Navigation Acts restricted colonial trade to benefit England, emphasizing the economic prioritization.
While other goals such as spreading Christianity, civilizing missions, and political control were also part of British colonial policy, the primary objective remained economic gain. By controlling trade and production, Britain aimed to strengthen its economic position against imperial rivals and secure wealth for the empire.