After President Lincoln’s assassination in 1865 and the loss of a third son in 1871—two others died in 1850 and 1862—Lincoln’s emotional state deteriorated until, after some erratic behavior, the two police officers showed up at her door. She was institutionalized, released months later, and lived out most of her remaining years overseas. After her death in 1882, historians—all of them initially male—began to mine her legacy, advancing a questionable theory of lifelong mental illness that remains hotly debated today. … Early portrayals of Mrs. Lincoln as unhinged and volatile were followed by claims that she suffered from bipolar disorder, a diagnosis which, of course, did not exist in her lifetime.
Michelle Dean dives deeper into the First Lady's quirky behavior:
She was reputed, before she arrived in Washington, to be a woman who haggled over every purchase, strawberries particularly. And Baker claims that Lincoln’s estate was only the size it was because Mary sought out every available source of funding for official matters other than the President’s own pocket. The obsession with money led to that disastrous sale of fancy clothing and to the act of sewing her entire inheritance of fifty-six thousand dollars, just before her commitment, into her skirts. You can read that as parsimony or greediness, but what it boils down to is control….
There is evidence that even before the Presidency Mary was prone to shopping binges, when there was money for it. Some historians think this further evidence that she was bipolar, with a mania that expressed itself as acquisitiveness. It is hard to say if they are right. There are certainly people in this world who could testify to the satisfaction of impulse buying, and to its fleetingness, without falling under psychiatric scrutiny.