Though it draws on a tradition of civil rights activism stretching back to the mid-20th century and beyond, The Black Lives Matter Movement as such began in 2013, when activists Patrice Cullors, Alicia Garza, and Opal Tometi began using the hashtag #BlackLivesMatter in response to George Zimmerman’s acquittal in the killing of Trayvon Martin—a Black teen who had simply been walking back to his father’s house from a nearby convenience store when Zimmerman thought he looked suspicious, confronted him, and shot him. Though Zimmerman was a member of his neighborhood watch and not a law enforcement officer, his actions served as a reminder of the disproportionate policing of Black bodies in the US, as white supremacist myths about Black criminality lead police to use unnecessary and unjustified violence against Black people.

In the years after 2013, numerous incidents of police violence against Black people made national news and confirmed the movement’s view of the problems with policing. Prominent examples include the 2014 killings of Michael Brown in Ferguson, Missouri, and Eric Garner in Staten Island, New York. In My Grandmother’s Hands, Menakem writes at length about the killing of Tamir Rice, who was just 12 years old when Cleveland police found him playing with a toy gun in a city park and—mistaking the toy for a real gun—shot and killed him.