The false belief that systemic racism is in the past is widely perpetuated, and (aside from the blatantly obvious police problem) many do not realize we are still very much a country which operates on white supremacy.
The most powerful book in transforming and informing my position on racism was DiAngelo's "White Fragility: Why it's so Hard for White People to Talk About Racism." I highly recommend this to everyone.
Some other great books are "How to be an Antiracist" by Ibram Kendi and "Privilege, Power, and Difference" by Johnson.