As the word intersectionality falls from the lips of Hillary Clinton and increasingly is normalized and sanitized, we should be clear about its radical moorings. In fact, the idea did not begin in the academy but in struggle. Last year marked the 40th anniversary of the Combahee River Collective, a Radical Black Lesbian Collective. The concepts of “simultaneity” and “intersectional feminism” capture Combahee's grounding in the radical Black feminist tradition. As Barbara Smith, one of the co-founders of the Collective pointed out (pdf), "simultaneity" is the signature contribution of Black feminism. That is, race, class, gender, sexuality are in play at the same time. They intersect. They operate simultaneously.