30: Martin Luther King Jr autographed portraitEstimate: 4,000 5,000 A spectacular signed portrait of Martin Luther King Jr Georgia born preacher Martin Luther King Jr was the de facto leader of the American Civil Rights Movement. He led the Montgomery Bus Boycott in 1955, the Birmingham Campaign (1963) and the March on Washington (1963). It was in the nations capital he gave his iconic I Have a Dream speech. King was shot dead by a white supremacist in 1968. He continued to be a defining