NEW YORK (AP).- As Black History Month begins and Abraham Lincoln’s birthday approaches, the New-York Historical Society adds to its displays a rare handwritten copy of the Thirteenth Amendment to the Constitution—the measure that abolished slavery—signed by Lincoln himself. The document, which was recently acquired by David Rubenstein, managing director of The Carlyle Group, is on view at New-York Historical in the new Robert H. and Clarice Smith New York Gallery of American History. “I am honored to have recently purchased an Abraham Lincoln-signed copy of the Thirteenth Amendment, and am pleased that the first public exhibition since my purchase will be at the New-York Historical Society,” said Mr. Rubenstein. “Along with the Bill of Rights, I believe the Thirteenth Amendment is the most important addition to the Constitution, and I hope as many people as possible will have a chance to see th