Yo, this goes for all my brothers and sisters locked down
For all my peoples incarcerated, for those who ain't make it

from Wu-Tang Clan – A Better Tomorrow Lyrics on Rap Genius

Meaning

Locked down is a term for prison as it is a term for saying that when you are born in the ghetto you are born in a cell/prison that comes with less money and less choices.

The more freedom you have the more power you have and a way to make sure that they never have power is to keep them imprisoned in the ghetto and lock their freedom.

This goes out to not just the imprisoned, but to those who never came out of jail/ghetto in the literal meaning (as in died).

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