The US Sentencing Commission studied federal sentences from fiscal 2017 to 2021. After accounting for factors like criminal history, Black men received sentences 13.4 percent longer than white men, and Hispanic men received sentences 11.2 percent longer. Much of the gap came from the decision of whether to impose prison at all.
Some disparities were written into law. The 1986 federal drug law punished crack cocaine 100 times more harshly than powder cocaine, and crack defendants were mostly Black. Disparities also enter through choices made before sentencing: who is stopped, what charges prosecutors file, and who gets a plea offer.
The Supreme Court accepted statistical evidence of racial disparity in death sentences in McCleskey v. Kemp (1987), but ruled it was not enough to prove discrimination in an individual case. That ruling still makes system-wide sentencing bias very hard to challenge in court.