London Williams stood in Black Lives Matter Plaza in Washington, D.C., moments before the verdict was read in George Floyd's murder trial Tuesday, wondering how he would cope if the white police officer who killed the Black man was acquitted. Then, the verdict came for former Minneapolis Officer Derek Chauvin: guilty on all counts. Williams, 31, doubled over with emotion, covered his face and wept. With that outcome, Black Americans from Missouri to Florida to Minnesota cheered, marched, hugged, waved signs and sang jubilantly in the streets. But they also tempered those celebrations with the heavy knowledge that Chauvin's conviction was just a first, tiny step on the long road to address centuries of racist policing in a nation founded on slavery.