Many see Mary Todd Lincoln as one of the worst first ladies in American history. Sure, she may have spent like Imelda Marcos, and yes, she dabbled in seances and brought spiritualists to the White House. But could there be another reason why she gets such a horrible rating? Todd faced unimaginable loss before, during, and after her stay at the White House. She also may have suffered an undiagnosed and mood-altering illness for her entire life.