The minstrelsy era is definitely not an era to ignore and it always surprises me when I think about how I never learned of this time in school.  During high school we of course covered slavery and the like but we never covered minstrelsy and I only knew of it because of a class I took in my first year at George Mason.  The politics behind minstrelsy are strange to me in the sense that just within 100 years, society could change so much.  Racism is still alive today but it may not be as in your face as minstrelsy was.  Minstrelsy was blatantly racist and took from African music forms, appropriating the music and exaggerating stereotypes of black people.  It seems that as society progresses, we become much more in tune with the rights of others.  Similar to how we find it atrocious to hit animals such as pets like our dogs or horses.  Years ago this was accepted but that is no longer the case today.  As society progresses it seems we speak up as a people to what is right and what is wrong.  The norms of society change and while I cannot say why exactly, I believe there is a small faction of people in opposition of the way things are done and as time progresses, that faction grows until the majority of society believes what is being said is correct.  It could be that the idea of black face was wrong to some people but no progress was made until those people started talking to others and explaining why black face was wrong.  After talking with others and communicating we begin to become exposed to new ideas and new information.  As we learn more we start to realize what may be acceptable in society and start changing what is acceptable, moving towards a society where we can all enjoy each other without abuse.