What were the justifications for imperialism ?

answer:

Americans justified imperialistic behavior by: Claiming that it was their responsibility. Americans and Europeans both claimed that it was their responsibility as superior races to uplift, civilize and Christianize native peoples. This was known as the White Mans Burden and was based upon the ideas of social Darwinism.

Explanation:

besides the fact that abraham lincoln abolished slavery, and greatly benefit black people, he had a heavy impact of the definition of what democracy was, and should be.