I'm sure that there will be a few references to the Aunt Jemima trademarks in upcoming law review articles. Let me direct you to a handful of court decisions regarding the mark. The cases offer an important look at how judges saw race & commerce in the mid-20th century.
The courts here effectively concluded that only one company could sell flour (or syrup) branded with the caricature of a black-skinned person.
PhaZZer defaulted in the litigation and the district court awarded $7.8 million to Taser. On appeal, the Federal Circuit quickly issued a R.36 no-opinion affirmance in 2019. Then, in February 2020 the USPTO finally cancelled the claims of the asserted patent (via reexamination). US7234262.