The Smithsonian’s National Museum of African American History and Culture commemorates the 50th anniversary of Martin Luther King Jr.’s final human rights crusade in a new exhibition on the “Poor People’s Campaign,” a multicultural coalition that began in 1968 to end poverty. The exhibition, “City of Hope: Resurrection City & the 1968 Poor People’s Campaign,” features rare archival film and new oral histories with people who helped organize the campaign including Marian Wright Edelman and Andrew Young.