On April 4, 1968, Martin Luther King Jr., age 39 — and to many, the personification of non-violent protest — is assassinated in Memphis. Over the following week, unrest sweeps through cities nationwide.

Buildings are set ablaze, businesses looted, and at least 43 people are killed. Federal troops are called into several cities. Marines mount machine guns on the steps of the U.S. Capitol.

On April 10, the long-stalled Civil Rights Act of 1968 — including the Fair Housing Act and… the Anti-Riot Act — is signed into law.

In many cities, the physical scars remain for decades. Urban property values drop across the board, as white people hasten a migration to suburbs outside of city limits. For decades, Black communities will be culturally isolated from the rest of their cities.