University of Miami journalism professor Tsitsi Wakhisi remembers Trayvon Martin. Ten years ago, Sybrina Fulton joined the Black mothers’ crying line. She had lost her 17-year-old son, Trayvon, after he had walked too slowly in the rain at his father’s housing complex in Sanford. It made his killer, George Zimmerman, think he was “suspicious.” Since then, more Black mothers have joined Fulton in the crying line, and still more are coming. But Black mothers have been crying for centuries, mourning the sons they got … but did not get to keep. Not in America. Whether slave owners yanked your child...