Black people that fight for black people?

Please do not be so stereotypical. But to Answer your question, anyone can fight unless they have a disability or something of the kind stopping them.

Because union fought to free slaves.

That is much debated topic. There are several websites that seem addresses this. There seems to be many individual cases where one black person did go with his master but he was mainly a servant....

It is not just black people who are abused. All different races of people have been abused by their own race or by other races at one time or another. There is something evil in all of us that makes...

Yes, in relationships, in neighborhoods, in parks, in simple vicinity; all is possible and happens all of the time.