Caste: The Origins of Our Discontents by @Isabelwilkerson dives into its case that the US has a racial caste system with compelling empirical and anecdotal evidence. I audio-booked this and found it to be a good delivery for this book. Recommend.
Caste: The Origins of Our Discontents (audiobook)
Caste: The Origins of Our Discontents by Isabel Wilkerson