File -- A 1964 file photo shows then U.S. Attorney Gen. Robert F. Kennedy in his office in Washington, D.C. Kennedy owned one of 48 printed copies of the Emancipation Proclamation that were signed by Lincoln, and now the copy Kennedy purchased in 1964 is being sold by his widow, Ethel, in a Dec. 10 sale at Sotheby's. (AP Photo)

File -- A 1964 file photo shows then U.S. Attorney Gen. Robert F. Kennedy in his office in Washington, D.C. Kennedy owned one of 48 printed copies of the Emancipation Proclamation that were signed by Lincoln, and now the copy Kennedy purchased in 1964 is being sold by his widow, Ethel, in a Dec. 10 sale at Sotheby's. (AP Photo)