@John_Jacob, do you really feel black people born in America could be successful if they only tried harder? Is that what you're basically saying, that there is an even playing field for them, and they can go as far as their talents will take them?
Because, if so, that's a load of shit.
Historically, since reconstruction in the South, the plight of black people has been one of oppression and rules specifically designed to disenfranchise them in one way or the other. They introduced voting regulations that included literacy tests....but would include grandfather clauses that would allow poor illiterate whites to vote. Separate but equal school boards? Sure, sounds great until you realize all the resources go to the white school, while black children are forced to do with lesser equipment. Buying a home to create generational wealth....ever hear of "red lining?" Which was a process where it was impossible for a black family to get a cheap, government backed loan to buy a home, while they were literally giving them away to white families. Then we can look at the environmental racism, which forced blacks to live "on the wrong side of the tracks" metaphorically speaking. Black communities frequently have highways/expressways going through them, or rail traffic. The pollution and environmental hazards are significantly worse for these communities. You talk about marriage rates in the 60s compared to the 90s. There are multiple reasons for the decline, and part of it is the racist war on drugs. They made it so that possession of crack held a significantly higher penalty than powder cocaine. It might shock you to know that blacks used crack more while wealthy white people used cocaine...So, the jails became full of black men for selling drugs, or the suspicion of selling drugs, which broke up families and caused a generational shift that nobody saw coming...and those communities are still feeling it today.
Basically, blacks have had the deck stacked against them since about 1870...And obviously chattel slavery before the Civil War wasn't good for them as well...