America is and always has been systematically racist.   

African slavery held that those enslaved were of a lesser humanity, if human beings at all. That lead to African Americand being viewed as lesser peoples by Americans in general, North and South, liberal and conservative alike. As time passed those holding that view have diminished but the culture of racism is built into the system.

Examples:

a young black male is five times as likely to be incarcerated as a young white male;

the average African American family has a net worth between an eighth and a tenth of the average white family;

only 3% of the top 1% is black versus 13.4% of the American population.