John H. Baker, "Lincoln, Mary Todd," American National Biography Online, February 2000, http://www.anb.org/articles/04/04-00632.html.
Mary Lincoln's tenure as a first lady coincided with the Civil War. During her first days in the White House, when Confederate units were unopposed in northern Virginia, army officials encouraged her to leave the city, but she insisted on staying and even accompanied her husband on tours of the Washington defenses. Like many other women, she nursed soldiers in hospitals, often inscribing their dictated letters to relatives in the North. Lincoln was unusual in her commitment to raising money for the support of impoverished former slaves ("contraband"), who crowded into Washington. However, her good works never stilled the criticism of her extravagance when the allowance for the White House was exceeded, nor did she ever shake the gossip that, because her half brothers fought for the Confederacy, she was a spy.