I'm all for 'black history' as long as all other ethnic groups are represented in similar electives.
Although, in most of the history classes I went to we never really discussed the race of the person. sometimes if they immigrated here you would get hints ( "he immigrated from Germany in his 20's", a fairly safe bet he was white)
but nobody sat up there and said " ‘poor Richards almanac’ was written by Ben Franklin. A white man "
basically we studied what happened the names of the key players and what they contributed.
when race was mentioned it usually was to point out that the person was of a minority group. I found the mentioning of the race of the person kinda condescending and insulting to the man (sort of like 'he accomplished these great things in spite of his race'. instead of letting his deeds speak for him, and ignoring the irrelevant)
I'd think a special class in black history would be an amplified version of this. if I felt my race (or ethnic group, gender, religious group) wasn't fairly represented, my push would be to point out people who where overlooked, the greatness of their contributions and have it included in the regular history class.
having a regular history class and a separate class for black history would tend to give the impression that the historical contribution of blacks(or others) couldn't compete to stand out in a regular class and need a special class oriented just on them for their contributions to be noticed (not true at , but that is the impression I’d expect people to take from the situation).
to me a special class for black history while not providing them for all the other groups gives the appearance of the black contribution as sort of a 'special Olympics of history', if I was black I imagine I'd be terribly offended.