@gets - I'll just make a brief response to #3 since you agree on the rest.

Didn't say that other groups didn't experience abuse and discrimination, but nevertheless none compare to the black experience in America. The group that comes second are Native Americans then the Chinese. Much of the alleged discrimination against the Irish has been exaggerated, such as the "No Irish Need Apply" signs (recent investigations found that this sign was never actually used). There were a few lynchings against Italians in American history and there was some prejudice against southern Italians when they started arriving en mass starting in the 1890s, and some anti-Mexican lynchings and discrimination. Yet whatever discrimination there was against Irish, Italians, Germans and Japanese there was, they don't compare to black Americans, Native Americans and Chinese immigrants, and of those, black Americans received the worst treatment. That was my point.