Ever since the document was examined several weeks ago, it's been a mystery. Initially, it appeared to be a reproduction of the terms and conditions of Confederate Gen. Robert E. Lee's surrender in Appomattox, Va., in 1865. But staff members of the Civil War and Underground Railroad Museum in Center City - who came upon the document while preparing for the museum's relocation - soon noticed pen indentations in the paper, and darker and lighter ink strokes consistent with handwriting. They also found a notation in a 1935 museum inventory identifying the document as an "original." Could this artifact, crudely...