A well educated Southerner, she was known for her vivaciousness, wit and spirited personality when she met the lowly lawyer Abraham Lincoln in 1839. Their marriage of 25 years produced four children, and proved to be volatile at times with Mary's high strung temperament. Mary's life was marked with many losses - starting with her mothers' death when she was 7, the death of her second born son Eddie in 1850, followed by beloved Willie in 1862. It was after Willie's death that Mary invited spiritualists into the White House so that she could attempt to communicate with her dead sons. At least eight séances were held, and Mary felt their presence in her life, writing to her sister that, "Willie lives. He comes to me every night and stands at the foot of the bed with the same sweet adorable smile he always has had. He does not always come alone. Little Eddie is sometimes with him..."

After seeing her husband assassinated before her eyes in 1865, Mary's life was shattered. She left the United States in 1868 and lived for two and a half years in Europe with her son Tad, who died at the age of 18, in 1871. In the 1870s Mary attended séances under assumed names, at which Abraham may or may not have "appeared." She was photographed by William Mumler, a "spirit photographer." Concerned about his mother's sometimes irrational behavior (and spending jags), Robert Lincoln, Mary's surviving son, petitioned the courts to declare her insane in 1875, and she was remanded to a Bellevue Place, private sanitarium for 3 months. Declared sane again in 1876, she spent many of her remaining years in France, never forgiving her son for his betrayal, and died in Springfield, Illinois, in July 1882.