The main reason would be because so many of them had already died fighting against the British.
This clearly repudiated the Supreme Court’s notorious 1857 Dred Scott decision, in which Chief Justice Roger Taney wrote that a Black man, even if born free, could not claim rights of citizenship under the federal constitution.
It was mainly the "C. Imperial nations, such as the United Kingdom and France," that benefited most from 19th-century imperialism, since these were the nations that were extracting the resources from the colonies.
Answer: They used the excuse that since Hitler made girls wear skirts that were longer that made him a religious person.