Ayodele Olosunde, assistant general counsel at the United States Department of Justice, threw down a challenge to members of the Mathews Branch of the NAACP. He was the keynote speaker for the group’s annual Martin Luther King Jr. Day celebration, which was held virtually on Feb. 7 and can be viewed online.

“I charge you today, NAACP Mathews, let us hold America to its great promise,” he said during a virtual celebration of Black History Month. “The change we want is in your hands. You are the change. Break the silence. Speak up and act out.”

The challenge came at the end of an address in which Olosunde honored King and called for a celebration of such firsts as the election of the first Black female vice president and the first Black senator from the state of Georgia, and the appointment of the first Black defense secretary. But he laid out in stark terms the issues still facing communities of color.

“Black health is under duress,” he said. “Black bodies, Black socioeconomic...