In Gadsden, Alabama, a roadside marker honors civil rights protester William Lewis Moore's murder.

In Gadsden, Alabama, a roadside marker honors the life and death of William Lewis Moore, a civil rights protester murdered during a walk. The silence surrounding Moore's murder troubled one man for years, prompting him to start a campaign for a marker commemorating the event. This story is part of NPR's year-long investigation into the complex and confusing landscape of historical markers in America.