List one idea over which imperialists and anti-imperialists disagreed

I think they disagree with the division of wealth. Imperialist wants to control and have all the wealth while anti-imperialists wanted an equal distribution of wealth among the people. A nation's wealth should be shared with each other.

Explanation:

The Anti-Imperialist League was founded on June 15, 1898, in Boston in disapproval of the winning of the Philippines, which happened anyway. The anti-imperialists rejected the expansion because they thought imperialism disrupted the credo of republicanism, particularly the need for "approval of the governed".

Many issues divided the imperialists and anti-imperialists. Those who supported imperialism pointed out its economic benefits for the colonizing countries, which would have access to new trade markets, resources, and labor. Imperialists also argued that they had a mission to improve other areas of the world. Anti-imperialists bothered with that, considering that colonialism was too expensive, invasive, and misled governments from developing also protecting the homeland.