At the Washington, D.C., ROADSHOW event in August 2010, Phyllis, a guest from Chevy Chase, Maryland, brought in a signed letter by Martin Luther King, Jr. dated 1958 that she had purchased at the estate sale of Nixon biographer Earl Mazo.

"First, I must admit that I was strongly opposed to Vice President Nixon"

At Mazo's request, King was writing to share his impressions of then-Vice President Richard Nixon, which seem favorable on balance until King's cautionary conclusion: "if Richard Nixon is not sincere, he is the most dangerous man in America." The letter was given an insurance estimate of $10,000 by expert Christopher Coover in 2010, which increased to $12,000 in 2014.

Read & learn more about the letter in this gallery.