Here’s a list for starters , but of course is no where complete.
1. NAFTA and subsequent trade agreements have given the world more of an advantage in supplying garments and other finished product, wiping out many jobs where blacks use to work.
2. H-1B, L1 and all of the other work Visas have taken away many US jobs and reduced previous high paying jobs to a non-sustainable and a non-competitive level.
3. Many jobs no longer available due to automation.
4. Many have gone off-shore, this gives the corporations a tax advantage
and allows them to hire and train as they will.
5. The abolishment of affirmative action and less oversight in defense jobs have eliminated many jobs.
6. Foreign students with cash is more attractive to US colleges and universities, than those coming to them asking for grants and loans.
7. Technology centers (outside the US) have sprung up to provide training to low paying young people – the said was NOT afforded to US blacks.

http://usblackunemployment.blogspot.com