The fact that Blacks want and desire the same qualities and values in life as any other group. We want freedom, respect, self-preservation, and the chance to live our lives based on character and not the color of our skin. Just as any other oppressed group, we knew we were equal and deserved equal rights so we fought until it happened (by law) at least.
I see this question as a positive one. What factors have helped? Certainly we can't forget the brave people of the Civil Rights movement in the 1950s and 1960s and beyond. We can make a list of movers and shakers who came forward during that time that helped to empower African Americans in society, politics, and at home at the local levels. Rosa Parks, Malcolm X, Dr. Martin Luther King, Jr. are only a few famous ones that start the list. The process was slow, but African Americans who got roles in the movies gave pride to their people. Sidney Potier won an academy award in the 1960s which helped to bring attention to his ability to be a leading character. Movies like "The Red Tails" and "The Help" which came out in the last year show those who stayed the course and fought for what they belived in during times of great prejudice. I'm sure we can think of others if we keep going, from war heroes to Barrack Obama, there are always those emerging when opportunities arise.
Lots of them... We can start with racism. This has been the main factor, in my opinion, that has made it so that it has been hard for African Americans to assimilate. It seems likely that they would willingly have assimilated in most ways but were blocked from doing so by things like segregation and other forms of racism that showed that whites did not want them to assimilate.