Bahamian-American actor and civil rights activist Sidney Poitier (centre) suporting the Poor People's Campaign at Resurrection City, a shantytown set up by protestors in Washington, DC, May 1968. The Poor People's Campaign sought economic justice for America's poor and was organized by by Martin Luther King, Jr. and the Southern Christian Leadership Conference. (Photo by Chester Sheard/Keystone/Hulton Archive/Getty Images)