On the night of President Abraham Lincoln's assassination, his frantic wife, Mary, calls for her best friend and confidante, Elizabeth Keckley, but the woman is mistakenly kept from her side by guards who were unaware of Mary Todd Lincoln's close friendship with the black seamstress. How did these two women--one who grew up in a wealthy Southern home and became the wife of the president of the United States, the other who was born a slave and eventually purchased her own freedom--come to be such close companions?    With vivid detail and emotional power, Ann Rinaldi delves into the childhoods of these two fascinating women who became devoted friends and confidantes amid the turbulent times of the Lincoln administration.